I used to believe in the 'traditional' [and by that I mean, the overly cliché societal PERCEPTION of] Karma. But the mountains fell and the seas drowned... And I was left with the mere sand they left behind.
I wouldn't say there was that 'infinite' amount that the traditional way has claimed - that "when you do and act of good, you will get good returned", and this will loop as long as you do good deeds. My view of it is, that there is a definite finite of karma.
As opposed to getting good received BECAUSE you did something good, you will receive good AT RANDOM. The main point here being, that because there's a finite amount of karma, if you're having a good day, then someone else would be having a bad day.
At least through this logic, I have some sort of lie to tell to myself when I have a shitty day; That someone else is having the time of their life because quite frankly, I'm pretty sure that if this karma thing is right, then I'm doing A LOT of people favours here.