Decoder Ring listeners write in with some excellent mysteries, and for our last episode of the year we’re solving three of them. Why do children play in boxes full of sand? Why do rock bands pretend like the show is over when everybody knows they’re coming back for an encore? And what was up with those school assemblies where you’d get to skip class to learn about…yo-yos? The voices you’ll hear in this episode include yo-yo masters ”Dazzling Dave” Schulte and Dale Oliver, children’s book author Rob Peñas, Pulitzer Prize-winning design critic Alexandra Lange, and music journalists Brian Wise, Michael Walker, and Travis Andrews.  You can find all the music from the segment about encores in this YouTube playlist. This episode was produced by Max Freedman, Katie Shepherd, and Evan Chung, Decoder Ring’s supervising producer. Merritt Jacob is Senior Technical Director. We had additional production from Joel Meyer. If you have any cultural mysteries you want us to decode, email us at DecoderRing@slate.com or leave a message on our hotline at (347) 460-7281. Get more of Decoder Ring with Slate Plus! Join for exclusive bonus episodes of Decoder Ring and ad-free listening on all your favorite Slate podcasts. Subscribe from the Decoder Ring show page on Apple Podcasts or Spotify. Or, visit slate.com/decoderplus for access wherever you listen. Learn more about your ad choices. Visit megaphone.fm/adchoices