I thought I had forgotten everything about secondary school. I thought I was done with it after the O' levels in 2006.

But when I received that text message from AA a few days ago, it felt like my past was rushing up to me, a swash of memories that had taken on that rose-tinted glow you'd associate with days you can only look back on fondly and wish Time didn't have to move on.

My secondary three and four years are distinguishable by the teachers, studying (mountains of homework that said teachers loaded upon us), my classmates, and of course, writing - all of these traipsing on to the ceaseless soundtrack of Time. He was, I daresay, the teacher who was closest to the class, who made the most effort and invested the most of his emotions in us. I remember his pep talks that made us cry, that made even him cry; I remember how he would constantly remind us how little time we have to the Big O (he'd make me SO stressed out!); I remember how he joined us in the hotel rooms at night to party on our Geography Field Trip to Perth, Australia, even though he wasn't exactly supposed to, being our teacher and all; I remember him inviting us to his bachelor pad during Chinese New Year - he was one of the few teachers I know who actually did that.

He didn't seem depressed then. But then I wonder how we can ever tell. Is there a checklist that we can methodically tick in order to find out who isn't as blithely happy as he seems? Now that I think about it, he used to cast his eyes down after a good laugh, as though he were wondering if that fleeting moment of happiness would last. Am I thinking too hard, reading too much into his expressions, digging for a clue that wasn't? Could we have known; could we have done something? Were we too early, or too late? He had done all he could to help us attain the best scores we could get for our exams. Could we have done all we can to make him happier, hopeful enough to live on, if not for us then at least for himself?

I didn't dare to look at him. The idea of a body in a coffin, with too much makeup, is too haunting. How can you stuff someone in a wooden box like that? Wouldn't you want to preserve the best memory of him? Granted, he was cremated ultimately, but I just couldn't make myself look at him, in that neatly-pressed suit and an inch of makeup on his face. To me, he'd always be the Math teacher who tried to imitate a koala bear during the field trip to Perth, and the one who acknowledged the effort I put in to my studies.

His Facebook page has 600 over fans, the last time I checked. I keep thinking about his students, those he'd taught before (like me), those who were about to be taught by him, those who were left without him all of a sudden, walking in to class only to hear the news of him committing suicide because of depression. I keep thinking about how they must feel, to suddenly lose him like that, if they felt guiltier than I do, like they should have known. I don't know much about his family, but I can't even bear to contemplate what they must be feeling, to have grown up with him and then suddenly be robbed of him because of a decision he made one day.

He was, in retrospect, a large part of my upper-secondary years. In that way, he was a large factor in affecting how I turned out.

Maybe the past never leaves you. Maybe it clings to the back of your mind, even if you think you've moved on like your life demands you to. I wish I can remember more of him. You never truly realise how much you've forgotten until you can't remember anymore.

Be at peace, Mr Ng. You will always be loved and missed.