Direction

Friends aren't people who are always there for you; no one's always there for you. Friends aren't people who need you, or care about you, or necessarily even like you. Rather, friends make you like yourself, make your better self come out just by being around. They act as a character springboard for the qualities you prize in yourself, allow you to grow in a direction you covet.

It is only in the subset of such relationships which are stable that this effect is necessarily reciprocated. Friendship, as here described, is a personal experience of someone else, not necessarily a shared opinion or sentiment. One's selection criteria for friends, then, must necessarily be dominated by the search for people who can teach them new things about themselves; the ability to reciprocate such benefits is often useful, and sometimes necessary, but ultimately it counts as an expense and must be weighed as circumstances dictate.