Mathematician Richard Schwartz on his changed view of things:
"...one thing I appreciate more now is that the state of human knowledge is full of holes. When you’re young you have the impression that almost everything is known, but now I have this feeling that almost everything is unknown about mathematics. There are these very thin channels that people have gone along, like ants following each other along a trail. You find these long thin trails of things, and most things are undeveloped. I have more of a sense of the openness of it."