"There was a time when the newspapers said that only twelve men understood the theory
of relativity. I do not believe there ever was such a time. There might have been a
time when only one man did, because he was the only guy who caught on, before he wrote
his paper, a lot of people understood the theory of relativity in some way or other,
certainly more than twelve. On the other hand, I think I can safely say that
nobody understands quantum mechanics."