Personally, I believe in karma for many reasons.
I've had a pretty crap life so far, so i'm expecting this to pay me off in later life, if not i'm knocking off my life. LMAOOOO. Erm... since i've been 10 my life went down hill, parents split up and that will probably affect me for the rest of my life. Hard to explain but it just will. I no longer have any grandparents and i'm constantly being urm hurt i'd say.
I'm owed something good, and i tell myself one day I'll get it.
Another reason why I believe in karma is i've noticed that stupid things i do, often have a knock on effect? If it's bad then i've noticed something crap happens, if it's good then i think it's noticable i'm being rewarded.
I'm ever so slightly cynical over Karma though, as it could just be a farse made for the hard working man that is always being stepped on, made for human's to lead their life under a false sense of believe that is generally a cloud over the true goings on.
D'you believe in karma, and why?