Things like that happen in our every day adult lives too. A word is forgotten in a text or a bit of gossip is misunderstood. It's a perfect tool to twist your plot. Send your protagonist to the wrong address or cause an explosive fight because of a mixed up message.
It's also a great way to trick the reader. What did the protagonist's lover really mean by that note? If the protagonist thinks the worst, so will the reader.
Simple children's games are a huge part of our fictional worlds. Games we all played as kids like hide-and-seek. A lot of horror stories have someone hiding from the stalking bad guy. Piggy in the Middle will have characters keeping something valuable away from someone. What about Hot Potato? I don't want the cursed ring, you have it. No, I don't want it! You have it. It gets passed back and forth, round and round. When the time is up, poor bloke that has the cursed ring is cooked.
What children's games do you see adult versions of frequently in stories?