People's personalities are up to them, but you're greatly influenced by your surroundings. Seriously, if you play Call of Duty all day, and all you hear is a bunch of miserable, hateful trolls calling each other "motherfather campers!" and other salty stuff, it's only so long until you start to act like them. If you want to be happy, surround yourself with happy people and do positive things, like volunteer, take control of your life (healthy eating, exercise, sun, etc). It's all easy, except people forget how easy it is, or don't see the forest for the trees until they're smack-dab in the middle. I hate to sound preachy, but I've cut ties with a few longtime friends over this. One because a stoner, the other a racist, and they quickly turned from good people to hateful, miserable trolls that would be bad for anyone to be around.