Never anger a dragon, for you are crunchy and you go well with ketchup. Sometimes it's easier to beg for forgiveness than ask for permission. Believe those who are seeking truth, doubt those who find it. To kiss a fool is bad. To let a fool kiss you is even worse.
Some mistakes are too much fun to only make once.
Think twice before you speak, especially if you intend to say what you think. If you always do what you've always done, you'll always get what you've always gotten. It is best not to swap horses while crossing the river. If you can't beat your computer at chess, try kickboxing. He who laughs, lasts.