I think I'd be depressed if everything were nearly all known, but I don't feel any danger of that happening.

It is an embarrassment that the dominant forms of matter in the universe remain hypothetical.

You're entitled to say, if you're so smart, why don't you tell me what that dark matter is? And I'll have to confess I don't know.

I think I'd be depressed if everything were nearly all known, but I don't feel any danger of that happening.