Knowledge is dangerous, which is why governments often clamp down on people who can think thoughts above a certain caliber.

Any sensible ruler would have killed off Leonard, and Lord Vetinari was extremely sensible and often wondered why he had not done so. He'd decided that it was because, imprisoned in the priceless, inquiring amber of Leonard's massive mind, underneath that bright investigative genius was a kind of willful innocence that might in lesser men be called stupidity. It was the seat and soul of that force which, down the millennia, had caused mankind to stick its fingers in the electric light socket of the Universe and play with the switch to see what happened - and then be very surprised when it did.

‎No one remembers the singer. The song remains.

I stroll along, talk, I sign books, people buy me drinks, I forget where my hotel is, I get lost and fall into some local body of water... done it hundreds of times.

By the time you've reached your sixties, you do know that one day you will die, and knowing that is at least the beginning of wisdom.

Everyone's heard of Erwin Schrodinger's famous thought experiment. You put a cat in a box with a bottle of poison, which many people would suggest is about as far as you need to go.

He had never been interested in stories at any age, and had never quite understood the basic concept. He'd never read a work of fiction all the way through. He did remember, as a small boy, being really annoyed at the depiction of Hickory Dickory Dock in a rag book of nursery rhymes because the clock in the drawing was completely wrong for the period.