Things I've learned... for women:
Never buy generic toilet paper.
Don't put Neosporin on a facial cut unless you want a visible scar.
Always pee right after having sex.
Invest in a Roth IRA whenever you have an extra $200.
Bleach: Seriously, a dab will do ya. No need to waste it.
Treat people in the service industry (waiters, cashiers, etc.) with respect.
If his friends are douchenozzles, don't marry him. If you're looking for excuses that include, "Well, his friends are douchenozzles," definitely don't marry him.
Single men in their 40s are single for a reason.
Quality time is over-rated; it's how the quantity time is handled that counts in the end.
Your parents are human, yet you will think you make more mistakes than they did.
Don't salt your food before you take the first bite. If you're a guest at someone's house, don't salt the food at all. Unless the hostess is out of the room.
"Sir" goes a long way... "ma'am" slightly less than "sir," but better than "hey."
The best hangover cure -- instantly -- is scrambled eggs, hair of the dog, and three ibuprofen.
And, things to never change for a man: Your university, your career, your goals, or your hairstyle... you will regret the change and resent the man.