So, I was in a card shop today looking for a funny birthday card.
And all of a sudden I came across THIS:
http://imgbox.com/5WgKw8I2
On the outside (has you can see) it says "2 Rules in Life: 1-Neverdrink on an empty stomach".
And on the inside it says "And 2-Never fart in a diving suit. Happy Birthday!".
I must say I was a bit surprised seeing this, because it's the first time I've seen anything referenced like it in any card.