Well, you’re constantly driven by your curiosity, and you’re constantly frustrated. So it’s a bit of both. I don’t know. It's like… it's like asking an explorer what happens if you’re… exploring a strange bit of the world? There are hardly any bits left now, but in the past, say, exploring a bit of the Amazon jungle. Obviously it’s dangerous, it’s interesting, you don’t know quite what you’re going to discover. It’s a mixture of all those things. It must be, in a certain sense, reasonably pleasurable or you wouldn’t go on with it, you see, I mean, if it was thoroughly distasteful, shall we say. But it’s not unalloyed pleasure because you’re not getting any feedback or getting results, you see. Much easier… the ideal thing to do is if you do experiments in which every few days you get a nice, positive answer. And then you go on and do another one and get a positive answer. Then you get reinforcement all the time, and then you’re really very cheerful and happy. But in this work, certainly… and that’s why it helps if there are two of you because if one of you gets a bit downhearted, the other one is probably, you know, in a more buoyant mood, and carry you along. But it’s not to be recommended for everybody, I can tell you.