Why do we expose so much of ourselves to someone? We give up so much to make them happy. We lose ourselves in them, becoming them. And call it "love". Not realizing how unhappy we've become. That your old self is gone. That your favorite color isn't even your favorite color, it's theirs. That you, don't even care about yourself anymore..
And if they leave what's left? Nothing? Emptiness? We beg them, cry for them, and ask them to stay....why?? Because we've stopped loving ourselves. Because without them we will have loved for nothing.