"I always want to try to understand why things work. I’m not interested
in getting a formula without knowing what it means. I always try to
dig behind the scenes, so if I have a formula, I understand why it’s
there. And understanding is a very difficult notion. People think
mathematics begins when you write down a theorem followed by a
proof. That’s not the beginning, that’s the end. For me the creative
place in mathematics comes before you start to put things down on
paper, before you try to write a formula. You picture various things,
you turn them over in your mind. You’re trying to create, just as a
musician is trying to create music, or a poet. There are no rules laid
down. You have to do it your own way. But at the end, just as a
composer has to put it down on paper, you have to write things
down. But the most important stage is understanding. A proof by itself
doesn’t give you understanding. You can have a long proof and no idea
at the end of why it works. But to understand why it works, you have
to have a kind of gut reaction to the thing. You’ve got to feel it."
– Sir Michael Francis Atiyah