“Mysteries are facts that haven't been formalized.”

“The best evidence that time travel is impossible is the fact that we haven't been invaded by hordes of tourists from the future.”

“I just came this morning and haven't been debriefed yet about the status of our latest prisoners. As a matter of fact, I'd barely stepped inside,”

“No matter that they had been together for years, always a feeling of formality when they first saw each other again, even if the separation had been only hours. It had something to do with the attention [he] paid to her – the fact that he never took anyone’s return for granted.”

“We are full of words whose true meaning we haven't been taught, and one of those words is suffering. Another is the word death. We don't know what they mean, but we use them, and this is a mystery.”

“Lots of things are mysteries. But that doesn't mean there isn't an answer to them. It's just that scientists haven't found the answer yet.”