my top 10:
Never try to please a woman, (it's can't be done) just focus on not pissing them off.
It will never be as good as the first time.
The more time you have to do something, the less likely it will get done.
It's okay to stop eating when you feel full at a buffet.
No matter how reasonable an idea seems to be, there will be people against it.
Never give expensive electronics as gifts; it's rarely what they really want.
The best time to buy groceries is 3am
Take at least one vacation a year with a plan to do absolutely nothing.
If it tastes good, don't ask what's in it.
Get used to the fact that you're surrounded by idiots