There's a social media thing called the "What The Fluff Challenge," which is basically a peek-a-boo game with your dog. You hold a sheet or blanket in front of your body . . . then let it go as you duck away and hide.
The dog sees the sheet fall, but you're not there. And it blows their little puppy brain. It works best if you're near a doorway. The whole thing was started by a woman in the U.K. Y'all try it. Send video . . . please!