Reddit top voted comments...
That the toy monster steals their toys at night. Specifically the ones that aren't put away.
When I was little, I built a Lego remote control for the TV. My dad was like, hey, see if it will change the channel. I kept hitting it, nothing. All of a sudden, a few channels change and I'm screaming and jumping up and down. Then it stopped working. My dad goes "That was magic, awesome Lego remote!" Thanks, Dad.
My kids were getting the vaccinations and the whole trip there I told them that getting shots in the eyeballs was the most effective way. They were terrified! When we got to the doctor's office and the nurse came in with the needles, I said, "Isn't it true that getting your shots in the eyeball the most effective way to prevent future illnesses?"
She said she heard about a study they were conducting and didn't know the results. She then looked at my kids and asked if she could give them their shots in their arms instead... You never saw kids so happy and excited to roll up their sleeves in your life. All smiles and no tears.
As a child, my parents told me if I did something bad I was going to "baby jail". I believed in baby jail until I was like 12 years old. If I started crying in a public place my dad would say "Mary, stop that. You don't want to go to baby jail, do you?" And then I would just scream louder like "I don't want to go to baby jail!" I was kind of a well behaved kid until I realized baby jail wasn't real. Then I turned into a teenager and they told me that Juvenile Detention was a thing and I didn't believe them.
That, as their father, I could change their names whenever I wanted to.
One time I pretended to get on the phone with the "Arizona Name Registry", and renamed my two kids Snargle and Gorf because they kept misbehaving.
They were bawling. I could barely keep a straight face.