Is it a selfish world we live in? When we do something nice for someone, they become happy, AND you too become happy because they are happy. So..indirectly, you made yourself happy.
When you do something for God, what is it that you want? Eternal life. So..it's something for....YOURself.
When you feel guilty, say sorry...whatever's right...who feels better? You. You've done your part, you've said sorry..sure you could be sincere, but the deed is done. Now the wronged party HAS to forgive you. Otherwise, it's their fault. See..it's not your problem anymore. This is the best. You do something wrong, hurt the other person, feel sorry, say sorry, feel better cos you've satisfied your conscience. The other guy? Has to deal with the crap you dished out, has or should accept your apology, and has to move on. This is a real kicker in the nuts. So 2 wrongs on you makes the other guy feel right.
Yea..that's what I have to say on selfishness. Am I angry? Course not, I'm just as guilty of always wanting to do the 'right' thing.