He picked up a twig and flicked it at the fence. Nothing happened.
He "bravely" touched the twig to the wire. Nothing.
You can probably guess what comes next.
"So I dropped the twig and grabbed the wire with my hand. I mean, who wouldn't?" said Greenstein, now 61 and an editor and writer in Philadelphia.
"I got electrocuted and it hurt, I mean, it really hurt. I jumped back and I look back and the entire crew is looking at me with these blank looks on their faces. One of them finally said, 'Why did you do that?' and really - why did I do that?"
Every year, holiday safety stories warn people to make sure they stay secure on ladders putting up lights, keep candles away from curtains, and make sure carving knives are sharpened properly.
Doctors say the holidays brings out extra alcohol-fueled or kitchen-catastrophe injuries, but we're stupid and human all year long. Taylor Swift posted pictures of her bloody finger bandage after a 2015 kitchen knife injury, and Jimmy Fallon nearly lost his finger after his wedding ring got caught on a countertop. (Maybe we should just avoid the kitchen.)
After I wrecked my back relocating a 20-pound cat off my lap, I posted a message on Facebook asking about stupid human injuries and got about 100 comments in less than a day. People happily offered up the details of their ridiculousness, some even offering photographic proof.
They stabbed themselves with meat thermometers, injured themselves changing a duvet cover and tripped over many cats and curbs and stairs. Sneezing and sleeping are particularly dangerous activities for back injuries.
How big a public health risk is stupidity? Hospitals don't keep a record of injuries caused by embarrassing behavior. The Consumer Product Safety Commission focuses on the problems with products, not people. Safety tips are usually aimed at keeping children safe, not adults. We're supposed to have outgrown that.
"We had a young man who had a sty on his eye and his father encouraged him to take care of it on his own - and offered him the use of his hunting knife," said Ann P. Murchison, director of the Wills Eye Emergency Department in Philadelphia. "I think the idea was to lance the sty using the hunting knife? Thankfully he didn't do anything to his eyeball, but his eyelid didn't fare as well."
Murchison said most injuries are due to falls or allergic reactions, but some of them are people doing really - there's no other word for it - dumb things. Like trying to curl eyelashes with a curling iron. Or using regular glue to put on false eyelashes and gluing their eyes shut.
Some weird incidents are completely unpredictable. Several years ago, Christine Radlinger Solina, 46, a school bus driver in Deptford, New Jersey, was attacked by a "murderous underwire bra" shortly after midnight on Thanksgiving Day.
She was getting undressed for bed and took off her shirt, not realizing that the underwire had broken and poked through the middle of the bra.
"When I went to take my arm out of the sleeve, I gashed my wrist on the wire and had to drive myself to the ER because the kids were sleeping and the husband had to stay home with them," she said.
She ended up with five stitches - and the doctor on call was a classmate of her husband.
"Needless to say, I was the entertainment for the whole hospital staff; they were all coming in saying, 'Can I see it?' " she said.
Mark Krill, 36, a software engineer near Tampa, said most of his injuries are because "a lot of the time I think I have better abilities than I do." He had many examples of embarrassing injuries, including the time when he separated his shoulder trying to race some teenagers on a BMX course and crashed. (He said he'd been able to keep up with his 4- and 5-year-olds just fine.) He sliced open his hand trying to open a new grill with a Leatherman pocketknife and now can't feel anything in one of his fingers.
And then there was the time he was on his way to a date. He got a blowout, pulled over to change a tire, and a highway patrol officer offered him a crowbar to help pry the tire off. The crowbar rebounded and smacked Krill in the face. He ended up with a nasty black eye when he went to meet his date. She's now his wife and is the one who nominated him for this story.
The stories abound. Amy Milner, 47, in Brooklyn, New York, was attacked by her duvet cover. She was trying to shove the comforter into the cover when she "punched the crap out of my arm between my shoulder and elbow." She ended up with a massive bruise that took a while to heal. (We discussed the inside out and the roll methods.)
Paul Leingang, 27, now a graduate student in marine science at the University of Delaware, was working at a doggy day care in St. Paul, Minnesota, when, trying to stop a dogfight, he smashed his head into the corner of a heater hanging from the ceiling.
"I had a concussion and seven staples on the top of my head and the doctors were all like, 'Did you not SEE the heater there?' " Leingang said. "What was crazy was that I tried to finish my shift and I started to hallucinate all these dogs barking at me. I'm sitting in this warehouse with 40 dogs barking at me, trying to figure out what was real as I'm bleeding from the top of my head."
Then there are the injuries that, decades later, leave the victim unsure how they happened.
Tracy Rowland, 50, is a video editor in Jersey City. She once fractured her skull with . . . a butter knife.
"I was using it as a lever to pry off the back of my stereo speaker. It wouldn't budge so I put my face right down there to see what was holding up the process and the knife slipped out - but I was still pushing hard so it did a catapult-level THWACK right between my eyes, causing a hairline fracture in the part of the skull right above the nose hole," she wrote, adding that she was roundly mocked in the ER.
Oddly, she has volunteered for Habitat for Humanity for years without injury. Perhaps that's because she is using the correct tool for the job, she suggests.
"Power tools aren't as dangerous as butter knives in my capable hands," Rowland said. "I think when you're using something that's labeled as 'dangerous,' you tend to pay more attention; household items just sneak up on us."