An expert is a man who has made all the mistakes which can be made, in a narrow field.

If quantum mechanics hasn't profoundly shocked you, you haven't understood it yet.

Einstein, stop telling God what to do!

Anyone who can contemplate quantum mechanics without getting dizzy hasn't understood it.

Those who are not shocked when they first come across quantum theory cannot possibly have understood it.

If you think you understand it, that only shows that you don't know the first thing about it.

If anybody says he can think about quantum physics without getting giddy, that only shows he has not understood the first thing about them.