I think it's important to recognize the lessons life has dealt you. Here are a list of mine.
-People will only change when they want to, not when you want them to.
-Just because a relationship didn't work out with you doesn't mean it won't work out with someone else.
-Everyone has exceptions to their rules.
-Half the things you gain that you had previously thought you wanted more than anything, you don't really want once you have them.
-It really does take all kinds of people to make the world spin.
-Everything keeps on happening around you whether you're in the midst of it or holed up in your room somewhere.
-It is better to dance and look like an idiot than to never dance at all, or worse, only watch others dance.
-The friends who let you get into trouble because they know you want to and will protect you while you're in the middle of said trouble, are more important in life than the friends who never want you to do anything that might cause a stir anywhere.
-Sometimes you outgrow people, and that's okay.
-People will never cease to surprise you.
-Sometimes you get hurt. Sometimes your heart breaks. You can't help what other people do to you. You can only change your response.
-Jealousy is a waste of time.
-If you want to eat your feelings, okay, just run an extra mile in the morning.

I'm sure there are more, but I wanted to document these in case I forget them later on.