Soul mates

People think a soul mate is your perfect fit, and that's what everyone wants. But a true soul mate is a mirror, the person who shows you everything that's holding you back, the person who brings you to your own attention so you can change your life. A true soul mate is probably the most important person you'll ever meet, because they tear down your walls and smack you awake. But to live with a soul mate forever? Nah. Too painful. Soul mates, they come into your life just to reveal another layer of yourself to you, and then they leave. And thank God for it.

Liz Gilbert in Eat Pray Love

Personal opinion: I love the way the term soul mate is defined above. I think it is a great definition for some relationships. I believe some people step into your life to teach you something and learn something from you and then go. And you should let them go when the time comes. But I'd rather stick to the the popular definition of soul mate, although I am skeptical about finding it these days. Lucky are the ones who do.