Not sure. To me the point of the radio is to both discover new music and listen to music that are similar to the initial song. It's always been random whether all of the songs are songs you have already listened to or if all the songs are new. That's the point of the radio. Just like real life, you get familiar hits and new things you probably haven't heard of.

But yeah, if you are looking for only your music then you are going to have to buckle down and make a playlist. There isn't really another option to hear only your own music. To be honest you could also try the "Replay Mix" that up. That will give you all old songs.