Just read this one in the monastery, and had to record it for posterity:
Billy never liked to wear boots. He always wore shower flipflops when he was driving a plane. Turned out he never went through the Escape and Evasion school, so they sent him, and he showed up the first day in those shower clogs. The instructor asked him how long he thought he'd take to get out of the jungle in them if he got shot down. He answered that it took him two weeks the first time, nineteen days the second time, and eleven days the third time.