Sometimes when you do a good deed for someone, they are just simple w**k**s, and proably have a shit life .... so feel sorry for them....
I have a firm belief .... if you do a good turn , it always comes back to you, you never know when , but it does...
You feel better from doing it ,and you know you did the right thing, and you dont have the worry from doing the wrong thing either ..... even if the guy was a s**t