That little tidbit of info is thanks to my Dad when I was a kid. Saw a half one with shreds lying all around and couldn't for the life of me figure out how that happened.That's what it is. They are shredded. I had no idea there's a nut in the center.
If you look at a shredded one closely, you can see the little hollow where the nut was (or find one interrupted and the nut will be visible).