Have you ever found a song that you loved at the store, and after looking through your collection discover that you already own the song? I've done iti a couple of times...and wasn't happy about it!!
Oh, books...... I keep picking ones from the library that, 20 pages in, I realize I've read before. " Oh, this is the one with the woman who didn't know she had a twin sister and the sister is the one who killed the butler and the grandfather is crazy and...."