How to Know

How do you know when to stop? When it's time to move on? Does it just hit you like a bullet? Or is it like a slow knife, where it takes time to seep in? Someone tell me, I don't know what to think anymore. I guess it's just hard to let go sometimes. I don't know about you, but I would always hear about these abusive relationships, and the girls who knew their man was cheating, and just let it happen. I always thought "Oh I would never end up like those girls." But you don't always get your way. A wise author once said. "We accept the love we think we deserve." But why do we think so low of ourselves? What does it take to realize were better then what we think? Then what happens when you get what you think you deserve? What would you do to keep your said person? Just don't end up like me, okay? Because life would suck as me.