Obsession is the beginning of most people's relationship, when one make up all kinds of reasons for why the other person is sooo awsome. So when one finds out that the feeling isn't mutual one hates the other person, or the feeling fades after a month...
Love is when one knows on a deep level that one is connected to the divine consciousness, and one is connected to every living organism, and that organism is you. Even if not so, one's thinking is linear, so love is a feeling, it's a state of mind not caused by something external...
(Of course you don't have to believe this)
