A visitor to Niels Bohr's country cottage,
noticing a horseshoe hanging on the wall,
teasing the eminent scientist about this
ancient superstition. 'Can it be true that you,
of all people, believe it will bring you luck?'
'Of course not,' replied Bohr, 'but…

Clifton Fadiman (ed.), Andrè Bernard (ed.), 
Bartlett's Book of Anecdotes (2000), 68.