Unfortunately, not many seem to comfort the comforters in my experience. This poem strikes a chord with me, as I've wondered about this same thing often.
...Yet, I have to wonder why this bothers me so much. After all, if my motivation for doing these things is to help, then I have achieved what I set out to achieve. Perhaps after all I am being selfish, doing good deeds to attempt to gain attention. In the end, I find that helping others really must be a selfless thing to be worth much.
And what they will not notice when you are present will do no more good for them to notice if you are gone.