A doctor came up to a patient in an insane asylum, slapped him on the back, and said: "Well, old man, you're all right. You can run along and write your folks that you'll be back home in two weeks as good as new."
The patient went off gayly to write his letter. He had it finished and sealed, but when he was licking the stamp it slipped through his fingers to the floor, lighted on the back of a cockroach that was passing, and stuck. The patient hadn't seen the cockroach - what he did see was his escaped postage stamp zig-zagging aimlessly across the floor to the baseboard, wavering up over the baseboard, and following a crooked track up the wall and across the ceiling. In depressed silence he tore up the letter he had just written and dropped the pieces on the floor.
"Two weeks! Hell!" he said. "I won't be out of here in three years."