This maybe has a John Denver feel to it, and it could mean different things to different listeners, and I honestly don't remember what I was thinking about when I wrote this.  Willing someone back into your life could be what this song is about.  Letting them know you're there for them, and the welcome mat is out.  This one might be for the one that got away who is now far away but you're letting them know they can find you and you won't turn them away.  It's universal, and I don't recall writing it about a particular past girlfriend.  It might be an acknowledgement to a former lover that you know it was wrong to break up, and that you know she knows it was wrong to break up too.  It could also be a metaphor for not ruling out the possibility of reunion, but knowing you both know it wasn't meant to be.  It could be about remaining open to returning to a former self, or to getting something back in your life that used to be there that you gave up but now wish you could have back.  It could be about not letting go of the past, or maybe it could be about knowing a lost love is thinking the same way about you as you are about her.  Oh yeah almost forgot - I like the melody on this one too - it's got some of that get-stuck-in-your-head quality.  It's a little bit country, but not enough to call it country.  Americana perhaps?