Lewis Carroll Quote

Like the goblin 'Puck,' it has led me "up and down, up and down," through many a wakeful night: but always, just as I thought I had it [the proof], some unforeseen fallacy was sure to trip me up, and the tricksy sprite would "leap out, laughing ho, ho, ho!"

Curiosa Mathematica Part I (3rd edition), Introduction (p. xxi)