People puzzle me

I don't understand how anyone could be so nasty, vindictive, and just plain mean. Maybe because I am nothing like that. And my best friends and family are not like that at all either. I feel pity for people who are so selfish, insecure, and have so much hate inside, that they take it out on others that they supposedly care about. It's a shame, because by doing so, they will only make their own lives miserable, pushing away people who care. It's very sad that often those people end up all alone with no one. What kind of life is that? Surely not a happy, fulfilling one. And yet they do it to themselves anyways. =(