Too often, and usually in younger people, we hear the saying "You Complete Me!" It's this false idea that someone else in your life will complete you. It's as if to say that I am less when I am single, but now that I have that special one, they are the finishing touch to make me and my life complete and whole.
Run as far away from thinking as you can!
You don't NEED to be with someone. And in fact, them bringing their broken stuff over into your life will only complicate you, and NOT complete you.
Instead, try shifting your thinking. Look at your partner and ask, "Do they compliment me?"