This seems obviously correct to me. In my experience this is not obvious to everyone and many people find it a bit distasteful to talk about. I'm glad you bring it up.

I haven't really tried hard, but I think I would find it pretty difficult to get myself to behave this way.

The way I "resolve" this dissonance is by thinking in terms of a parliamentary model of me. Parts of me want to be altruistic and part of me is selfish and they sort of "vote" over the use of resources.