What is the best piece of advice you could give someone?

What's the most important thing you've learned during your lifetime, etc.What is the best piece of advice you could give someone?
That it only matters what I think about me, not what anybody else does.What is the best piece of advice you could give someone?
Life is to be enjoyed. It is a gift. Accept the things you cannot change. Change the things that you can. And be wise enough to know the difference. Remember......nothing lasts forever.
love someone before you die. or you only have one life, live it to the fullest