Once is happenstance. Twice is coincidence. Three times is enemy action. (Auric Goldfinger, in Goldfinger by Ian L. Fleming)

Facts are the enemy of truth. (Don Quixote – Man of La Mancha)

It is much more comfortable to be mad and know it, than to be sane and have one’s doubts. (G. B. Burgin)

A mathematician is a device for turning coffee into theorems. (Paul Erdos)