A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.

"Beethoven tells you what it's like to be Beethoven and Mozart tells you what it's like to be human. Bach tells you what it's like to be the universe."

"Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so."