I think this song is about being obsessed with someone you don't really know well, who comes around sporadically, so you can't see everything about them, just the image of them you've made in your mind.
I think the part about "the only one" means that this person is the only one the speaker can love.
I think this song is about being obsessed with someone you don't really know well, who comes around sporadically, so you can't see everything about them, just the image of them you've made in your mind.
I think the part about "the only one" means that this person is the only one the speaker can love.