Further to this.
You come here because you want to. Not because you are asked or paid to do so. Your help is welcome but as with all things in life there are ignorant, greedy, forgetful, busy and just plain rude people that don't appreciate our efforts.
Just remember those times when people do say Thanks. Forget the times when people don't.
Don't come here if you are expecting praise every-time you do something.... Come here just because you want to help. Its like charity.