I really believed that I was on the right track, but that did not mean that I would necessarily reach my goal.

"I tried to fit it in with some previous broad conceptual understanding of some part of mathematics that would clarify the particular problem I was thinking about."

"I was so obsessed by this problem that I was thinking about it all the time, when I woke up in the morning, when I went to sleep at night, and that went on for eight years."