As far as the long term goes, I understand where you're coming from. It's a bit of a semantic game, as it's not too hard to argue that altruism is impossible and everything is ultimately done for yourself. That said, I think we differ here. I don't find the argument that everyone is equally selfish (only with different wants) compelling.

It gets complicated from here, though. You have to ask where these wants come from. Why does one person want the warmth of the needle, versus another wanting to change her child's diaper. Perhaps the ultimate selfless act is subjugating your wants in the first place, though I imagine you could argue this is also a selfish act. It could probably go on like this forever, but at some point you realize some people's circle of concern is bigger than themselves, and there must be something to this.