Why does love always cost us something?

I really don’t think love even exist until a sacrifice is required. Loving people who love us is an even exchange. Loving when we are hurt...now that’s real love. This does not mean it’s okay to hurt me. It just means I forgive you for hurting me, and I want you to stop hurting people for your own sake. It’s a fight for you not for me. I just get protected in the process. Really, love protects us better than we could ever protect ourselves anyway. We just can’t do it for ourself, or it’s no longer love. John 15:13 “Greater love has no one than this: to lay down one’s life for one’s friends.”