Selfless Good Deeds?

So this morning I was on the bus to school (which by the way! I was very happy I was not late for!) and I sat near the front of the bus and like any other good, courteous person I got off my seat when I saw a mother and her son get on the bus. So as I kindly got off my seat, I remembered a friends episode I had watched the night before. On that episode, Joey and Phoebe were arguing about selfless good deeds.. and if they even exist! Personally.. I don't really know if they do. I mean, come on, honestly...there is some pride that you get when you help someone in need. Is that joy.. if you can call it that.. really considered selfless? Is there a difference between doing a good deed and doing whats expected of you to do? I guess it all comes down to having good karma.