The transition from lover to friend to nothing

- So, you meet someone who does something for you. Maybe they sat next to you in Chemistry and had a certain "something" about how they plagiarized your lab notes; maybe your at a bar, and a different kind of chemestry happens (perhaps C2H5O5 related...) A million different ways that we start to fall in love.
Then, after a while, usually its not just one thing, but a bunch of things that conspire to test the relationship... For me, it was often about 3 months after the start. Little things at first, stuff that you've been meaning to bring up, to work out; how could this NOT be important to you? And from there, usually the break up.
And there you are, in this strange space where there are so many options and paths you could follow. Many times the relationship just "goes away", and gets filed under the "that was a mistake" category.  Yet, when you find pictures of that weekend getaway years later, doesn't it still flash to a smile in your mind, your heart? Was it really a mistake? Or was it just an adventure. And if we could be ok knowing it wouldn't last, would we still go in, knowing that we would have an adventure which would leave us with more knowledge, some moments of passion, and lessons, and smiles.
And what about the love you had?  Is it gone, or has it morphed into something else? Has it hidden or kind of "composted itself" into something else? Now, looking back, I can see different flavors of love for all these people that touched my life - some dim tendrils, some still smoking years later...
Sometimes the transition from lover to friend was natural, some times it was unwanted, some times it was only temporary.
The following song comes from one such transition from lover, to friend, to in this case, nothing beyond an etheric memory or the "was".  This was from some time in the late 80s I think. Didn't even have a title on it -

Once you were the joy of my heart, the thrill of my mind, a hand upon my soul,
once you had a face that shown alone, a way that was your own, and me.
But then we loved in such a different way, you were my every day, and I your every night,
once you were, but now you can not be, I understand you see,
I don't need you, and you most certainly don't need me.
But still, some how, we're friends.

(C) 2011 Dave Cox