There was once a boy with only a head, and his father loved him and managed to raise him until he was twenty-one. On his twenty-first birthday, his father took him to a bar and said, "bartender, give my son here a beer, its his 21st birthday!"

"Cheers, mate!" the bartender said, and he poured them both a beer. The father tipped his son, the head, back and poured some beer into his mouth. The boy swallowed, and one arm popped out.

Seeing this, his father gave him another sip, and out came another arm!

The father continued this until his son had a full body, torso and everything. It was wonderful! But the father gave his son one last sip and, and the boy then died.

Seeing this, the bartender said, "Sorry to say, it's the cardinal rule of drinking, mate. You should quit while you're a head..."