What we sow is what we shall reap,that's a universal truth. So we should be conscious in all we say and do.
Selfishness leads us to ill will in thoughts and deeds, having us to do wrong for our wants not our needs.
No the sting don't return as it was given, it comes when we lest expect it and from someone or somewhere without reason.
Afterthinking off all the senseless acts I've done, I can now say heloo to Karma for everyone.
Karma not only works for the bad it also recognize the good, so give what you expect to get, and do unto others as you would have done unto you.
Karma-At anytime can catch you by surprise, so don't question the things that unfold before your very eyes. Just recognize it as:
KARMA!