What does it really mean to "own" something? What does it mean that some thing "belongs" to you?
It doesn't mean that you are the one who made it. It doesn't mean that nobody had it before you or that nobody will have it after you. It doesn't mean that nobody else will ever use or borrow it. It doesn't mean that you have absolute control over what it is and does or what it will be and do – because we are all limited by the natural constraints of the universe and you are only human, aren't you?
So then, maybe it means that for that thing (that thing that you own)... you are home. You are that place it always returns to if ever it leaves, and you are the one who owes it the most care.
And maybe, if ever a person can truly belong to another (in willing spirit and not by physical claim) – maybe I belong to you. For you are the home to which I will always return. You care for me above all others (and that does not mean that nobody else cares for me but that I give you the most opportunity). You've staked your claim and I've accepted it. Nurtured it. You do not control me but you do own me.
I am yours and you are mine. We belong to each other.