It's all about mindset..
If you go through life thinking negative thoughts, you'll put yourself in a bad mood, and everything will seem negative.
But if you switch up your mindset and have a "glass half full" outlook on life you'll feel and be a lot happier.
Instead of thinking that something could be better or complaining that something isn't good enough. Change that self-talk up and instead say it could be worse.
You can apply this to almost every aspect of your life. Say you got an 80 on your last math test. With a negative mindset you might be beating yourself up about it and thinking how it would've been so much better if you got a 90 or a 95. Sure a 95 is a better grade than an 80, but you can't change your test grade. So instead think to yourself "well it could've been a lot worse, I could've gotten a 70 or even FAILED" I guarantee you'll feel a lot happier if you take this approach, and you'll study even harder to get a better grade the next time around.
Your mind affects your mood. And small adjustments in your thinking and outlook can drastically improve your mood.
XX Hannah Noelle