"Number 73!" All regulars are laughing, hard. They shout out in turns "73!", and laugh again. Confused, the person asks what's so good about 73. Says a regular

"Number 73!" All regulars are laughing, hard. They shout out in turns "73!", and laugh again. Confused, the person asks what's so good about 73. Says a regular, catching his breath and wiping tears from his eyes: "Heh 73, we haven't heard that one before!"