A friend visited me the other week and left a pack of chewing gum in my living room, which I've been trying to give back.

This got me thinking.

I don't chew gum. I've never chewed gum in my life; to be honest, I have no idea what people get out of chewing gum. Which is not to say I have a strong opinion that it's a pointless exercise; I don't doubt that there is something to be got out of it. I just don't happen to know what it is.

So if I'm perfectly willing to concede that there's probably some reason why chewing gum is a pleasant thing to do, why have I never had an urge to try it?

It seems to me that there's a certain class of activities which I might perfectly well find pleasant if I tried them, but which I feel no particular urge to try. I think they're things which I've encountered in such a way that my brain pegged them as Things That Happen To Other People. I feel no obvious hole in my life which would be filled by a piece of chewing gum in my mouth, and it's just never seemed worth the effort to go and chew on one anyway to see if I discover that the hole has been there but unnoticed.

Smoking, I now think, is another such thing. I've always believed that I never took up smoking because I was exempt from the peer pressure at school; I was part of the hard-core out-crowd which no amount of deliberate conformity could have made cool, and therefore nobody had any interest in pressuring me to start. This viewpoint has come under some fire recently as I began to acquire friends who smoked, and discovered that in fact most of them didn't start due to peer pressure at school, but instead took up the habit as responsible adults while under no more pressure than ‘hey, that looks fun, let's have a go’. And it would never have occurred to me to start smoking for a reason like that. It's not that I consciously decided not to because it's expensive, addictive and dangerous (although I might well have if I'd actually thought about it); I never really took the conscious decision at all. Smoking has always just been something that some people feel a desire to do, and I don't.

Come to think of it, I think I have much the same attitude to believing in God. I first encountered religious people in one of my numerous primary schools at age eight, and after my first serious communications failure something clicked in my mind and I thought ‘Oh yes, now I remember reading about this God who some people believe in, this must be one of those people’. I don't think I had any real concept at the time of wondering who was right, and I certainly didn't start considering whether to begin believing in God myself; I just registered that the person I was talking to subscribed to a lifestyle choice which people like me didn't, engaged tolerance-of-differences mode, and left it at that.

I wonder what distinguishes this class of activities. I don't respond like this to everything that people-who-aren't-me do. Some people go skiing, for example, and I've never been but I'd quite like to some day to see if it's as much fun as it sounds. That isn't a thing-other-people-do, for me: it's a thing I just haven't got round to doing yet (this categorisation is unaffected by the fact that I might never actually get round to doing it). And it too is expensive, dangerous and could be metaphorically addictive; so what's the fundamental difference between skiing and smoking that makes me think I'd like to try one while I've never so much as considered taking up the other?

I wonder if this distinction is something that only makes sense in my own head. Do other people see a category of activities which other people seem to enjoy doing but which it would never occur to them to try themselves? Or is it just me?

(Another thing that this has got me thinking is that I must be pretty bored if the sight of a pack of chewing gum can inspire profound philosophy!)