The same happens to me sometimes.
¿Really? What kind of music playlists and musical genres do you select and usually put on in the background when that happens to you? 
As for the rest of your comment, I have the hunch this post will answer many of your doubts and questions and probably will satisfy some of your concerns too. 
Uhm, mostly progressive metal in my playlist, some odd ones here and there, moondog, classical, etc