For several years I worked on writing a book, The Chimpanzee of Gombe: Patterns of Behavior, in which I was going to summarize the research results of the first 15, 20 years, whatever it was. And as I went in deeper and deeper into this, I realized that to write the kind of book that I probably should, I needed to learn all sorts of things which I would’ve learned had I been an undergraduate, which I had never learned, which had always made me feel a little bit at a disadvantage if I was talking to a real scientist. So the Ph.D., yes. But what about all this ground work, all this learning about endocrinology and things like that? So I taught myself these things in order to write the book, the things I felt I needed.