You ever have anyone leave an imprint on you? Such as you can't shake them out of your mind? Not so much you have deep feelings for them like you love them or anything, but something about them you just can't shake, as though they are meant to be in your life for some reason or another.
You care for them, yes, that is a given, but to what extent, un-known.
At some point one of two things will happen, that person will either walk out of your life completely, not ever knowing what purpose they would have played in it or they will stick around and fate will play out it's cards, whatever it may have in store, even if it ends in despair or joy.
