Teacher’s Day: How a 𝑷𝒂𝒊 𝑲𝒊𝒂 in School Became a Teacher to Inspire the Next Generation

“Only the brave should teach… teaching is a vocation. It is as sacred as priesthood; as innate a desire, as inescapable as the genius which compels a great artist.” 

Many would roll their eyes at Pearl S Buck’s lofty words about educators, but in the case of Dr Colin Tan, they ring true.

Not many of the teachers of his youth could have imagined that he would become a teacher himself, that talkative, joke-a-minute kid who was always getting sent out of class. But Colin clearly could not outrun his destiny. Today, he lectures on systems (embedded systems and operating systems) at the National University of Singapore’s School of Computing, putting his talent for talking to great use.

In this Teacher’s Day story, Colin tells us about his colourful past filled with eggs and exciting science experiments, and how drawing the short straw cemented his career in teaching.

What kind of a student were you? Can you share a few of the most, um, interesting experiences from your school days?

I was an “out-standing” student. Being a bit of a typical Leo, I was—and still am—a bit of an attention whore (my wife’s words, not mine). This made me rather disruptive in class, interrupting the teachers, talking loudly to other classmates, which resulted in me spending much of my time standing outside the classroom, or outside the Teachers’ Room. I spent the first three years of secondary school in the old St Joseph’s Institution building—what is now the Singapore Art Museum—and the Teachers’ Room was along this long corridor where most of the classrooms were. I was a pretty prominent fixture there almost every day.

At the time, there was a big field across the road from the old SJI, which is today the SMU campus. When I was in Secondary 4, my classmates celebrated my birthday by dragging me across Bras Basah Road to the field where they pelted me with eggs. It wasn’t anything vicious but more of a “tradition”. A few days, later we had another classmate’s birthday, so I wrote on the blackboard that everyone should bring eggs.

In between periods that day, we got all rowdy and the Discipline Master Mr Tang Wing Kee (who is still friends with me on Facebook to this day) came in to “calm us down”. He saw the announcement I had written on the board and told us sternly “Don’t you dare bring eggs!”

True to form, I brought a carton of eggs for the festivities, and as it turned out I was the only one. Mr Tang conducted a spot check and caught me. I was given two strokes of the cane on my heinie and the legendary “White Form” for “defiance of authority”, which my dad had to sign. Essentially, the “White Form” was a final warning that if I got into any more trouble, I would be expelled.  My dad was not impressed.

Another incident I remember was during the Chemistry ‘O’ Level practical. A good friend of mine (let’s call him “James”) and I discovered, to much glee, that there was concentrated nitric acid in the lab. While the invigilator was not looking, we snuck some of the acid into a test-tube and started pushing in something else we got from the lab to make a new chemical. We knew what we were doing, so it wasn’t in the least bit dangerous. At least not until I decided to push the said item in a bit deeper with a test-tube brush. The brush dissolved in the acid and released a brown gas (presumably nitrogen dioxide). We panicked and poured the contents of the test-tube into a sink, turned on the water releasing a big cloud of steam when the water touched the concentrated acid. We scrambled back to our seats just as the invigilator looked up. We sat innocently twiddling our thumbs as a cloud of steam hung around at eye level. Fun times.  

Indeed. What were some of your best and worst experiences with teachers?

I was extremely fortunate as a student growing up. I always went to mission schools—St Michael’s School (now St Joseph’s Junior), St Joseph’s Institution and Catholic Junior College—and the teachers have always been excellent overall. I don’t think I’ve ever really had a teacher that I would call “terrible”, although I feared my very formidable Primary 2 math teacher greatly. She comes from a prominent local family, so let’s call her Mrs S. Mrs S. was petite but had a presence that could be felt even before she arrived in school. I particularly feared her ruler, with which she would wield edgewise and rap us on the knuckles when we did badly. That hurt quite a bit. But she was an excellent teacher whom, at the end of the day, disciplined us because she wanted all of us to do well. I also had other great teachers like Mrs Chong, who spent recess tutoring me on my Mandarin when I was in Secondary 3, and Mr Sng, who did the same for me when I was in JC2.  

My Mandarin is still deplorable, but for the record it had nothing to do with my teachers.

As a kid what did you want to be when you grew up? Was teaching ever on your list? If someone told you at the age of 15, “Colin, you’re going to be a teacher” what would your reaction have been?

When I was really young I wanted to become a doctor, but I lost interest when I started schooling, probably because I was always an inquisitive person and there was so much to be discovered in life once I was released “into the wild”. When I was in Secondary 3, the first MRT services started, and my friends and I caught the train from Yio Chu Kang to Toa Payoh—the span of the entire network then—10 times ina single day. I was extremely impressed by the trains, so much so that I wanted to be an MRT driver when I grew up. 

At some point, I was also determined to become a priest. When I was about 16, I called up the Franciscan friary and inquired about joining them. I must have sounded extremely “kiddy” because the person who picked up the called laughed and asked me how old I was. When I replied “16”, he laughed again (possibly even harder than before) and told me to call back after National Service. Sadly, when I went to junior college I met a girl, and any thoughts of becoming a priest evaporated almost at first sight. Such thoughts never returned again. 

Finally in university, a friend and I wanted to start an IT-related business, but he managed to obtain a scholarship from a local bank and I took up a PhD programme, so that never came to fruition.

If anyone had told me at 15 that I would become a teacher, I would have brought them, with much concern and care, to the Institute of Mental Health for help.

We know from reliable sources that, in your youth, you’ve conducted a few “science experiments” that have gone awry, particularly one involving Pyrex cookware. Why did you feel the need to do so? Were you genuinely curious about science?

Ah, the Pyrex incident. “James” and I managed to get our hands on an old car battery. In those days, you could get almost anything from Sungei Road. We decided to make concentrated sulfuric acid, simply because. Since water has a significantly lower boiling point than sulfuric acid, we figured we’d boil off the water. A smarter duo would have left the Pyrex dish open and simply let the water boil off, but we decided to collect that water to see if there was any residual acid in it. Since the Pyrex cover had a convex shape, we placed it upside down over the dish so the water would collect and drip into a little bowl we had placed in the centre.

“James” and I stood over the dish and went “Ooooooh” when the first wisps of steam appeared, then, rather thankfully, stood back. I don’t really know what happened, but a few minutes later the dish shattered into a million pieces with a loud bang. That was when, I recall, “James’s” sister shouted down the stairs “WHAT THE F— ARE YOU TWO DOING??” and stormed down to the kitchen. Until today, I don’t know which I feared more – the fact that we almost lost our eyeballs, or his sister. We surmised that the acid had concentrated to a point where a stray drop of hot water landing back in the acid triggered a violent exothermic reaction that shattered the dish. If so, we were highly successful in our experiment, if we discount the fact that our original intent was to collect the concentrated acid.

I was always curious about science. I was extremely fortunate as a child because my parents didn’t send me to “enrichment classes” and instead pretty much left me to discover things on my own. My older siblings tended to leave their textbooks lying around, and I devoured them with a passion. I remember I read an experiment from my brother’s physics textbook, where you’d make a voltaic cell out of a stack of coins and cloth soaked in saline. I found a shirt that I assumed no one wanted,ripped it up and built my own cell. I had no voltmeter so I used the  classic tongue test. I stuck wires to the top and bottom of the stack and touched the other end to my tongue. There was that characteristic “taste” so I knew that my cell worked.

My brother also had a microscope set which I loved playing with. Sadly, I loved eating the salt and dyes in the set even more, so my tongue and mouth were often stained either red or blue. I was a curious kid, but not a bright one.

At any rate, my love for science prompted my parents to buy me an electronics kit. One of the experiments in the kit was to build “gates”, electronic circuits that computers use to make decisions. This ignited my love for computers, and every time we went out I would demand that my parents got me a new computer book, which I would devour in a matter of days. I learnt to programme at 10 and was drawing computer architecture diagrams by the time I was 11 or 12. Naturally I took up Computing in NUS, which led directly to me becoming a teacher.

What were your best subjects in primary and secondary school? What were your worst? Any memories of excelling or struggling in class? Did teachers ever do good old teacherly things like flinging your books out the window?

I was always good at science and math. Despite my checkered history as a student, I almost always scored A’s for those subjects. I was particularly good at Biology, never scoring less than an A1, although I didn’t score too well in C Math or Physics at ‘A’ Levels. I was extremely bad at languages, never scoring more than an E8 or D7 for Mandarin, and nothing higher than a B3 for English, although surprisingly I scored an A1 for Literature. I sometimes think the scripts got swapped and there’s some poor student out there with my C6. Another big surprise was an A1 for Bible Knowledge, of all things.

In JC, I was absolutely awful with Economics. I never got more than 20/100 for any essay. I thought that all this theorising about demand and supply and “production possibility frontiers” was just silly. Of course, I know better now, but I doubt I would do well in any economics or business-related subject.

Thankfully while I got routinely kicked out of class, no teacher ever flung any of my items out.  

Now that you are a lecturer in university, have you encountered students that remind you of yourself in your teenage years? How so? Do you have special words of encouragement for them? 

I guess the thing about teaching in a university is that I tend to encounter mostly very good kids. Nonetheless, I am always closer to the “naughtier” kids than to the more studious ones. These include the ones who have a mischievous or cheeky streak in them who go off on a tangent to experiment and try their own things, or do silly random things instead of spending all their time studying. As an example, I had a student, let’s call him “S”.  In my class, for the graded assignments, students should collaborate or do their own research to solve the problems we give them, instead of asking us. However, the students could still ask us for clarification on unclear or ambiguous instructions. “S” had a rather clever way of phrasing his questions so that I would inadvertently give out key tips; in other words, he would ask for answers without actually asking for answers. I caught on after one question, and told him “Don’t mess with me”. He stopped, but we remained close even after he finished my course.

He later became my Teaching Assistant in the same course.

I would say to all my students: Yes, grades are important, I would never deny that. Having good grades opens up many opportunities, not just here in NUS but also when you work. Nonetheless grades aren’t everything. Being curious, being confident enough to explore, doing a few silly things here and there, venturing out beyond your comfort zone to do things you wouldn’t normally imagine yourself doing, learn new things outside of your degree programme, hack up some code, serve your society—these are all as important as grades, and form you as a well-rounded and truly educated individual. 

Likewise to my students who aren’t doing well academically, keep your chin up. There are many more ways to shine than simply through your grades. Many of my friends who didn’t do as well as I did academically are today much more successful than I am. The important thing is to always keep learning, always keep exploring, always keep growing. Even now, I take on new projects and challenges to keep myself growing.

What made you decide to teach? What were your other career options?

This is kind of funny. We had a stern professor in our final year in NUS that we all feared. There was one week where we had three assignment deadlines in other modules, and a mid-semester test with this professor’s module. We decided to ask him to postpone the test. Since we all feared him, we decided to draw straws, and I was “lucky” enough to be chosen.

I walked to his office, and with great fear and trepidation, knocked on the door. He called me to come in, and, I, with superhuman effort, asked him “Prof, can we postpone the quiz?”

He immediately said “Sure! By the way, do you want to do a PhD?”

I said yes, and finished my PhD, applied back to my school to be a lecturer, and here I am now.  

What has been the most rewarding thing about being a teacher? 

I think the most rewarding thing is the positive impact that we have on our students’ lives. I’ve had students come back to tell me “I’m doing well today in this career path, and I chose it because you once said ‘blah blah blah’ and that piece of advice stuck”. I never remember saying anything wise, but somehow sometimes what I say sticks and guides students in their choices. My colleagues and I also believe in designing modules that ignite our students’ curiosity and love for the subject, and many times after taking our modules, some of our students who go on to apply what they’ve learnt from us to take part in international competitions, where they learn even more and their love for the subject grows even greater.

I always volunteer for Commencement Duty, where we sit on the stage in our fancy academic gowns and watch our students receive their degrees. One very cool bit is that my students would often drag their parents (and sometimes grandparents) to meet me. I remember one particular girl whose grandparents had flown in from India. She excitedly brought her grandmother to me and told her “Amma, this is the professor who always tortured us!” I guess that’s a great thing. Right?

How many cohorts have you graduated? Do you keep in touch with your old students? Have you inspired any of them to become teachers?

Many cohorts, at least 15 or 16. I keep in touch with some of them over Facebook, but rarely in person because everyone’s extremely busy. Some, particular those based overseas back home on visits, come to my office to say hello to me. I also had a student who came every year to give me mooncakes he baked himself. Many of them became teachers, particularly those students I had when I was a Resident Fellow at Sheares Hall. One became an NUS lecturer himself and is now my colleague. 

Have you met up with any of your teachers since you left school? Were any of them surprised you got into teaching? 

I met Mrs S (the fearsome Primary 2 math teacher) at the funeral of my Secondary 4 form teacher, and I went up to her and said hello. She didn’t seem too surprised that I had become a lecturer in NUS, I guess she’s seen even stranger things. But I did remind her of how she used to rap our knuckles with her ruler, and she said “Well, look how you turned out!”

What would you say now to that most horrible teacher you ever had?

I would say “Thank you”. I don’t think that there are any truly horrible teachers; teaching is a tiring demanding job that pays less than many other career options, and I often believe that only idealists become, or at least remain teachers.  I think that teachers are fierce because one, they have to deal with students like me every single day, and two, they want us to be our best.  Perhaps I’m being naive, but I think even the horrible teachers were trying to get us on the right path in their own ways.

What Gen X sensibilities (and nonsensibilities) do you bring to your teaching? You often post hilarious things online—do your students follow you on social media?

I do have many ex-students who are my friends on FaceBook, but not so much now. Believe it or not, I’m pretty close to the 5,000-Friend limit, and so I rarely tell anyone about my Facebook account. Most of my ex-student friends were from my Sheares Hall days. My current students rarely use Facebook anyway, and I don’t exactly think highly of new social media apps like Tik-Tok, so I don’t use them.

I guess Gen X was the most fortunate generation ever, because we didn’t suffer through poverty, war and political instabilities like the Boomers did, and neither did we have things like computers and social media when we were growing up. So we played outside a lot, we caught spiders and made them fight, and then got into fights ourselves. We played our own approximation of soccer, we played catching, we climbed trees, we push each other into the mud, we stuffed our faces with epok-epok and whatnots from street vendors, we explored cemetries and abandoned houses, we played make-believe Star Wars in the sandpit. In a nutshell we enjoyed the booming prosperity and political stability of the Singapore of the 1970s and ‘80s, without the madness and crowds of the ‘90s onwards. Most of all, we never had the toxicity of social media to tell us how inadequate we were.

So, as an aging Gen X-er, I would say this to my Millennial and Gen Z friends: forget seeing how great everyone else is on social media, forget following trends, forget advertising yourselves, forget Instagram, just go out and grab life by the b*lls, but remain faithful to your responsibilities.

Dr Colin Tan (BSc in Computer and Information Science (Hons) 1996, MSc (1999), PhD (2003), all from the National University of Singapore), is not yet 50. He is happily married.

*all photos were taken pre-COVID