Its basically saying that life is short, and you should not be wasting your whole life pretending to be someone else or making you seem like someone else, because its not gonna get you anywhere really, and you should just be yourself and people will most likely like you better!
I think that means to be yourself and live your life how you want, think your life is great don't think of other lives because you may think theirs is good but then when you start living it things start going downhill.
Explanation:
that sticks out to me because I DO try to live other lives when I have a perfect one already planned out for me. So I need to try to just be me and live MY very own life.