If the lecture is good, then everything is too smooth. That's the same in music: if the performance is too good, you really don't enjoy it, because it just goes by, and you can never penetrate into the heart of it. Sometimes a poor performance is better for enjoyment, because you can look at those things that were wrong and analyze them.

After I had written a paper or letter for Bohr, I always had the impression that I had learned something which I could use for my own work. And somehow, I never felt that I had too little time for my own work. I always found time.

This proving of such and such I found to be almost like cheating. You start somewhere, and then you go into a dark tunnel, and then you come out at another place. You find that you have proved what you wanted to prove, but in the tunnel, you don't see anything.

Werner Heisenberg Quotes