An old sailor puts on his old uniform and goes down to the docks oncemore for old time sake. he hires a prostitute and takes her up to a room. he's going at it as best he can for a man of his age. the old sailor ask's" how am i doing " the prostitute replies " well sailor you're doing about 3 knots?" he replies, "what that supposed to mean?" she says "your not hard, you're not in, and you're not getting your f**kin money back