One of the vivid memories from my youth which illustrates the general principle that kids are dumb enough to be their own worst enemies (and believe me, my childhood recollections may be spotty but those particular stripe of self-recriminations are in seemingly inexhaustible supply) is set during a visit to my grandmother (on my mother's side) who often took Little Bro and I for a week in the summer for no reason other than to give our parents a bit of a break. Grandma's house was not particularly big, nor was it located someplace cool like on a beach or near an amusement park of whathaveyou, and we never befriended any of the other local kids, if there even were any. (NB: this story references my paternal grandparents.) Grandma would make up for the lack of environmental entertainments by straight up buying us new toys to keep us occupied for the week. And one year, my brother chose a small glow-in-the-dark plastic skull filled with rubber creepy crawlies.
I couldn't say why he made that particular selection at the toy store that particular visit. It just struck him as cool and fun, I imagine. It wasn't specifically associated with any name-brand toy line, just a generic cheap novelty that my grandmother was willing to indulge him in. So into the cart and back to grandma's it went.
My grandmother's house had a large walk-in closet on the ground floor which was used mostly as a coat closet, as well as a storage place for the numerous puzzles and board games that my uncles had collected over time. It was a square room, small but still spacious enough that Little Bro and I could both step in and close the door and stand in the center without touching each other and without touching any of the coats, either. Since it was enclosed and windowless, it seemed like a good place to test out just how glowy the glowing skull really was.
So we went into the closet and closed the door turned off the light. I was the one holding the skull, doubtless having invoked some nebulous form of big brother privilege, the upside for Little Bro being that he could just stand back and appreciate the spectacle. And for some reason it got into my head that I should hold the skull up and make it nod while giving a menacing laugh, there in the pitch black depths. Which of course freaked Little Bro OUT and in no small measure freaked me out, partly because Little Bro's reaction was so immediate and terror-filled but also just in and of itself, the nodding glowing floating skull laughing at both of us, even though I was the puppet-master behind it, it still evoked some primal fear of things that could come out of the dark and get us, gloating and snickering all the while.
For a brief horrifying second Little Bro and I were both so freaked we couldn't even find and open the doorknob to get back out of the closet, but then we were back in the sunlit living room again, crisis averted. Still, the self-inflicted mental wounds had been dealt. The scars are relatively tiny today, but they're there, thanks to a dumb kid who liked a good scare a little too much.