In trying to figure out why my background kept reverting to the standard picture of yosemite, I noticed that almost(not every) time I booted my mac mini I got a new desktop. The old ones don't go away. I had 94 desktops in Mission Control today. Does anyone know how to make this behavior stop? It's really annoying to have to reset your background everytime you log in, just to have your iphoto pictures cycle through. I miss the days when my mac "just worked".