should we think about others everytime?

there are certain people who spend most of their life worrying about their friends. helping them out in any way he can, checking up occasionally on them, and the usual person that friends can run to. it had been his own will to help out others. and knowing that they're getting through it, makes him smile and proud. after all, he did what he has to. but the dilemma for this kind of people, is that when they are the ones who are caught in problems find other people useless. the friends he used to help couldn't help him. worse, his own advises aren't effective to him. he gets disappointed and frustrated. because he just realized that others can't help but only himself, which must be really hard. maybe that's why, it could look like selfishness. but what i could really say is this: if i have the time to worry about others, why can't i think for myself?