A good technical writer, trying not to be obvious about it, but says everything twice: formally and informally. Or maybe three times. - Donald Knuth

The psychological profiling [of a programmer] is mostly the ability to shift levels of abstraction, from low level to high level. To see something in the small and to see something in the large.

I can’t be as confident about computer science as I can about biology. Biology easily has 500 years of exciting problems to work on. It’s at that level.

The whole thing that makes a mathematician’s life worthwhile is that he gets the grudging admiration of three or four colleagues.