It's funny how that is sometimes, it's like a "music craving" or urge.... there are a few songs I can do that with pretty regularly...... (not the one in my head today, I have NO CLUE why that one is stuck in there!)
I had this song stuck in my head a week or so ago. It's a beautiful song, but I can already tell they are going to play it everywhere until I tire of it. Lol. Still, her voice is just amazing, and I like this song for now.