Schools don't shape character. I can't tell you what does, but I do know schools don't. School, as a former colleague used to enjoy telling parents, is a pipe. What goes in one end is what comes out the other, only hairier. If you doubt that, consider your own class at school and the variety of characters within it. And how much did those characters change during their schooldays? Exactly. I rest my case.

In the course of too many years in the classroom I taught several thousand kids. I don't remember many of them with clarity. But some I do and it is never because of their academic talent or its absence. It is because of character.

I taught two boys I'd describe as evil. One used to tape breadcrumbs to the inside of a window during the Canadian winter. Birds would peck at the glass. He cackled with delight at their frustration. This was a long way from being the worst thing he did, but it was indicative. The point was he didn't lack empathy. He knew exactly when he was causing suffering and he took pleasure from it.

I remember one, and only one, magnificent liar. Most kids lie badly. They give themselves away with their eyes or their hands. But this lad could convince me black was white. I once accused him of deliberately destroying a video recorder. I had strong evidence. But he denied it so thoroughly, so plausibly, so coolly, that I believed him. Years later we met by chance in a bar. ''Were you lying?'' I said. ''Of course,'' he said. I congratulated him. But I forgot to ask what business he'd gone into. I bet he's now rich.

I was good at spotting cowards. I recall watching a kid in a rugby team I coached manoeuvring himself around the pitch with apparent combative intent but always in such a way that he wouldn't have to make a head-on tackle. It took tactical awareness to achieve his aim, and skill to disguise it. I only saw through him because I'd done the same myself. I never told him he'd been spotted.

We all admire the qualities we lack. I admired courage, both moral and physical, and I admired nonchalance. There was one lad who really didn't seem to mind being in trouble. And he often was, not because he was bad but because he simply wasn't bothered. I'll call him Adam. At cricket practice Adam once threw a ball from the far side of the field without checking whether anyone was looking. He had a powerful arm. The ball hurtled through a crowd of kids who were all facing the other way.

The coach called Adam across and justifiably dressed him down. That ball, yelled the coach, could have killed someone. Adam stood there mute and meek. When the coach eventually finished pointing out the folly of his action, and it took a while, Adam looked up at him. ''I'm hungry,'' he said.

The coach had to turn away to hide his laughter.

And there were a very few kids, a very few, I remember just because they were irrepressibly cheerful. It's an endearing trait. And whatever Dale Carnegie may say in How to Win Friends and Influence People, you can't fake it. (I haven't read the book, of course. The title seems to me an oxymoron. Friends won by methods gleaned from a business book are not friends. They are victims.)

I taught one gangling shambles of a youth who seemed incapable of ill-humour.

If he was ever downcast it was only briefly. Something inside would bubble up in the form of a smile. And that smile infected others. He was a good sportsman and a reasonable academic, but people liked him because he just radiated geniality.

There are few people like that in the world. How they get to be like that I can't tell you, but they are beyond price. They add to the sum of human happiness.

I bumped into him at the airport a few months ago, the first time I'd seen him 15 years. The sunshine hadn't left him. He made me laugh. His name was Billy Dawson.

You may recognise the name from the news. He was bashed up outside a bar in Auckland early last Friday morning and he died the same day. He was 34.