I think karma does exist and it's something I do believe in. I think people confuse what that means though. Just because you do good things doesn't mean only good things happen to you. I've been through more horrific things in my life than most and the few that know my life story are gobsmacked that I have any faith left in humanity or that I haven't just checked out by now. I'd like to think of myself as a good person and I am good to others. Yes, some pretty shitty things have happened to me, but every experience brings with it a lesson. If I had to go through it all again to be who I am today, I wouldn't even have to think twice about it as terrifying as that would be.
There are people out there who do horrific things, and it would appear as if nothing bad ever happens to them and such, but sometimes karma works in strange ways and it's not always in ways we can see.
I may have been through a lot but I have a whole helluva lot to be thankful for. But I guess a lot of how you look at your life and others is a personal opinion. My importance is placed on the little things.
Success is partly your own doing and partly right place right time.