This is so very true. I just read "When God writes your love story" by Eric & Leslie Ludy. I met my love Andrew at church and after 7 years of friendship he became mine. We are now married and happier than ever. God molded us into exactly what each other needed. God is the core of our relationship.
It kind of stings when this happens.. ok, sometimes it stings a whole lot, but it teaches us valuable lessons about life, love, and friendship. May you never lose your sense of "doing that much" for someone else.