There's a wonderful book, by the way, Proofs from THE BOOK, of, well, simple beautiful proofs. The book is named after
> mathematician Paul Erdős, who often referred to "The Book" in which God keeps the most elegant proof of each mathematical theorem. During a lecture in 1985, Erdős said, "You don't have to believe in God, but you should believe in The Book."
> mathematician Paul Erdős, who often referred to "The Book" in which God keeps the most elegant proof of each mathematical theorem. During a lecture in 1985, Erdős said, "You don't have to believe in God, but you should believe in The Book."
https://en.wikipedia.org/wiki/Proofs_from_THE_BOOK