What is the greatest lesson you have learned so far in your life?

I have learned a lot of things so far in my life. The most important thing I think I have learned is to appreciate what you have. There's no point in wishing you could have something or someone you can't have. If you dont have that something or someone, that must me that it's not meant for you. I have learned not to feel sorry for myself since really my life isn't all that bad. Anything that doesn't kill you can only make you stonger, so I think that you should also appreciate the bad things that happen to you.