The main source of problems is solutions. — Problem

"If you think cryptography is the answer to your problem, then you dont know what your problem is."

"Heres how to look at problems: Problems are guidelines, not stop signs!"

"What makes a problem a problem is not that a large amount of search is required for its solution, but that a large amount would be required if a requisite level of intelligence were not applied."

"I spent a lifetime trying to avoid my own mental biases. (A) I rub my nose in my own mistakes. (B) I try to keep it simple and fundamental as I can. And I like the engineering concept of a margin of safety. I am a very blocking-and-tackling kind of a thinker. I just try and avoid being stupid. And I have a way of handling a lot of problems. I put them on what I call my too-hard pile. And I just leave them there. Im not trying to succeed in my too-hard pile."

"At a given moment, the time may simply not be ripe to solve a particular problem. Progress on something else might be needed first, and the necessary clue might come from a different direction. In the case of quantum gravity, the unexpected direction was string theory."

"Basic human problems can have no final solutions."