I'm not a very sentimental person. At all. But there is one song (and only one, really) that pulls at my heartstrings (in the sense that I can actually feel my heartstrings being pulled) when I hear it: Forever Young from the second Care Bears movie.
Man, that right there is my childhood. It's more than just nostalgia, though, but I can't quite put my finger on what it is about the song that affects me so.