Why do assholes prevail?

Why is it that the asshole people always seem like they are getting ahead in life over good people? Why can't the good guy, the little guy get ahead? I watch movies and I see how the hero always wins over bad. I wish I could see this in real life, at least once. Why do people tolerate assholes? I for one am trying my damnedest to not let assholes ruin, and or control my life. I am slowly but surely moving on away from their grip on me. Obviously I am still going to have assholes or rude, and mean people in my life, and I totally understand that. Like if I have a boss or a superior being rude to me there's nothing I can do, because I can't and won't jeopardize my job, but I'm gonna talk mad shit after they leave and I'm gonna feel good while doing it. I just want people to not think of just themselves so much and give a little thought to other people and their feelings. I'm not trying to say that I am perfect or that I give total thought to peoples feelings all the time. But I try, that's all I'm asking, if people try harder it might make a difference. I know this all sounds preachy or whatever you want to call it, but I remember how society as a whole used to be. Walking down the street you could actually say "hi" to someone or smile at them without them thinking you're crazy or you're trying to do something to them. I don't think we will get back to that point but it still is worth giving an effort towards the greater good.