It's pretty typical - and accepted - to care about one's own self, family, and friends more than random strangers simply because you have more information about what will make your self, family, and friends happy than what will make random strangers happy. If you want to make the greatest positive impact possible on the world, focus your efforts on where you have the most information, so that you don't accidentally make things worse out of ignorance.

That's not to say that you can't also care about the world. But it's both illogical and immoral to ignore the good you can do right in front of you, for the abstract notion of good that you might do for the world.