I was trying to find ways to look for genes that were so-called “rearranged,” to create diversity exclusively in the nervous system. I had tried a number of techniques, so I was very interested in this. And then I read a paper that really fascinated me, and this was on the olfactory system. It was estimated — of course, the olfactory system is the system that governs the sense of smell — and it was estimated that humans could sense at least 10,000 different chemicals in the environment as having a distinct odor. Even more surprisingly, chemicals that were almost identical in structure could have completely different smells. So “orange” versus “sweaty socks.” So this, to me, was the ultimate diversity problem, and I became completely obsessed with this. I thought this was it, I had to solve the problem. And the first question was, “How you can detect 10,000…” — some people say up to 100,000 — “…chemicals in the environment in the nose? How is that done?” It had been proposed that there were protein receptors in the nose, and some people tried to find them, but had not succeeded. So I decided that the first step had to be to find out how odor molecules or odorants are detected in the nose, and there was nothing that would dissuade me from doing that. That was it, nothing else mattered.