I worked for 20 years as a social worker, and that means listening to people's stories and reading them - and seeing how different they could seem through different eyes - and becoming part of them.

There's one old man lives in Harlow, and every time he sees me he'll charge over and shake my hand and tell anyone who's with me how I helped him get the home he's living in.

And the thing is, I've no memory whatsoever of what I did - probably just sent a letter to the council, and maybe rang them up a few times to nag them.

It's as if he's taken a vow to thank me whenever he sees me. There's been times I've found myself wishing he wouldn't, maybe when I'm in a hurry or something. But not really - he's a reminder of the way that sometimes something we do in the course of our life can actually make a difference, and most of the time we never even know. And that's a thing we need to remember, because it's just as easy to hurt as to help. (I'm only glad there's noone who makes a practice, every time they see me, of telling me how I really screwed up their life by some mistake.)