First, I think there are a lot of good interpretations given thus far, and I think they are all correct. It's what you take from the song. And about the guy's liking this song...it doesn't matter what songs you like and don't like. You are attracted to a song because of a certain aspect of your being has been touched. It can be rythmic, emotional, whatever. It just works. Now, what do I think it all means? I think she is declaring her love for someone. But, not just that. Right before the first chorus she says, "some kind of night into your darkness
colours your eyes with what's not there," She told her crush that she was in love with them, and they are just becoming aware of the crush. Then, it's turns into that other person's love toward her. "a stranger's light comes on slowly, a stranger's heart without a home, you put your hands into your head, and then the smiles cover your heart." There she is saying a stranger, being her, looking for a "home", or someone to love, and the crush is realizing this foreign feeling, and then returning that emotion, "smiles cover your heart." And the chorus is just repeating the fact that they are one now, but ironic that the crush never knew she had feelings before hand. A little confusing, I know, but it's hard to try and put emotion into words.
You got the whole song. In the end, smiles cover his heart. I think most people missed that. Thanks.