With their whole being, with all their forces, gathered close about their lonely, timid, up-ward beating heart, they must learn to love. But learning-time is always a long, secluded time, and so loving, for a long while ahead and far into life, is-solitude, intensified and deepened loneness for him who loves. Love is at first not anything that means merging, giving over, and uniting with another (for what would a union be of something unclarified and unfinished, still subordinate --?), it is a high inducement to the individual to ripen, to become something in himself, to become world, to become world for himself for another's sake, it is a great exacting claim upon him, something that chooses him out and calls him to vast things.

Rainer Maria Rilke -Letters to a Young Poet