On the other hand, I think I can safely say that nobody understands quantum mechanics. So do not take the lecture too seriously, feeling that you really have to understand in terms of some model what I am going to describe, but just relax and enjoy it. I am going to tell you what nature behaves like. If you will simply admit that maybe she does behave like this, you will find her a delightful, entrancing thing. Do not keep saying to yourself, if you can possible avoid it, "But how can it be like that?" because you will get 'down the drain', into a blind alley from which nobody has escaped. Nobody knows how it can be like that.
Excerpt from Quantum Mechanics by Richard P. Feynman (The Messenger Lectures, 1964, MIT).
Quite rarely do I find something so filled with common-sense, regarding a subject so far apart from common-sense as quantum mechanics is.
Later edit: Who knew Feynman practiced zen?