If I had five bucks for every time someone was having a crap time of it and asked "Why is this happening to me?", I'd have at least $47.50 (because some people just never pay up). And if I got 10 bucks extra for every time someone was having a great time - good mates, good health, good sex - the whole cigar, I'd still have the $47.50 that I started with above.
It would seem that the only time we ask ourselves "Why is this happening to me?" is when our lives feel like crap. When they're good, we don't ask any questions, cos we're too busy enjoying it.
So when I look at the question "Why is this happening to me?", it appears to me to be based on the assumption that life is FAIR, and to quote The Princess Bride, "Where is it written that life is fair?"
But to talk math-geek for a minute, life IS fair, because it's a random sequence of events - only part of which you or others have control over. (If you exclude the idea of kharma, that is) So if you accept the idea of randomness, you know you're going to have good and bad in your life. And if you're having a really crap time of it at some stage, statistically speaking (this is the math-geek bit) it would still fit in some aberration of "randomness". Perhaps you're just having a bad run of the numbers.. Similarly, when things are really going good, maybe you're in a good stretch.
I don't personally believe that things happen to people because they deserve them to happen. I just think they happen.
People, on the other hand, are not random and fall waaaaay outside any bellcurve. Your actions may or may not have an effect on their behaviour, but that's just part of life too.
Don't let the numbers get you down...