doesn't it usually feel good to do good? whether or not you're thanked for it, whether or not someone else appreciates it...you've still done it, and you know that. being angry about it probably doesn't feel good. forgive me if i sound sanctimonious. i'm usually a petty bastard, but in this one regard (at the least), i think i remain true to this attitude.
however, i approve of physically abusing the elderly on general principle.