I've had a lot.
"Don't run while pissing", ' if you pis, make sure you don't do it on a policeman". And some none pis ones: "never try and sleep with a girl while the other one hasn't left yet", "girls are humans, not objects", "******s are also people". And some "helpful" ones: "never lie to yourself", "treat your family with respect, even if they're annoying" and "don't fall asleep in a public area".