It doesn't. If you want other people to get what they want, then when that happens, you get something you want. You have to trade it off against other wants, but everybody has to do that, even people who only can't decide what to have for dinner.
Do all preferences work this way, or are there some which don't have to be traded off at all?
These questions really should go in the "stupid questions open thread", but I can't seem to find a recent one. Thanks for taking the time to answer me.
If it's worth saying, but not worth its own post, even in Discussion, it goes here.