The test I used which I stumbled on was to see what it was I was gossiping to people about. What you’re telling people, what you gossip about is what you’re interested in, and that’s what I found I was telling them about, so I decided that’s what I must be interested in. And exactly how that interest arose isn’t very clear, except that they are two of the things which appeared mysterious unless you answered them, you had to accept a more religious explanation, which I was reluctant to do on general grounds. So, I think that was the key thing that made me choose those two things, those two areas of biology. And some of the areas which one might have gone into, I didn’t want to go and… in… in… work on certain parts of physics, I didn’t think I was good enough as a theorist, and the… some of the experimental parts were getting things for teamwork, and didn’t look so interesting. So, there was no particular appeal in what I did… the little I did know, which wasn’t very much. So, it was very easy to make a change. So, it was a very unusual situation. Very few people find themselves in a situation like that.