"She buried her ears into the calm of his heartbeat, and in a matter of seconds fell terribly in love with the way her loneliness fell softly and suddenly, asleep, in his chest." Quote by Christopher Poindexter.
I've always thought about relationships this way. If I can't see myself with this person for the rest of my life, I'm not wasting any more time than I need to with them. Simple as that. I have far more important things to worry about right now.