Compare Yourself to a Celebrity
This is a really great way to get miserable. No matter how good you might be feeling about your life, you can always find somebody whose doing better in the pages of OK magazine. Any you will never be as pretty or have such great abs.
Mind you, neither will they! These people are so photoshopped they don't even recognize themselves in the mirror. The they end up having surgery to look like they think they should and you end up with.. Jacko...
On the other hand, if you wanted to be happy, forget celebrities and try and live in the real world for a bit. we might not be perfect, but we can have happy lives even with all our imperfections.