Why does BAD things happen to good people?

I haven't killed anyone, hit or even punch someone before , ever!! Once me being stupid , a girl came to me asking for money for baby food (for her brother) and i gave her �5 cos i felt sorry for her and then you'll never guess what i saw, 10 mins later i looked across the road and i saw her coming out of shopping store with her mom holding about 5 bags of food. i was like WAAAAAAAAAAAAAA! so i though oh well at least i was kind enough and something good might happen later but no, i just recently lost everything i worked hard for, why meeee??