wasabi, i've read the complete collection of captain cook's personal logs, and his voyages in hawaii.
from what i can what decipher, ayrton was bombarded by a hawaiian "foo" bird.
foo birds are particularly adept at crapping on tourists heads, making them a favourite of the locals.
seeing this, the local inhabitants began the tradition that foo poo was a lucky omen, giggling every time they saw it.
thus began the expression: when the foo sh!ts, wear it!
(please, no one pm me. i just made this up.