What have you broken or damaged by your own stupidity?

When I was 18, Dad and I were adding aluminum siding to the garage. Lacking a truck, we would buy a few lengths of siding at a time. They were 10 or 12 feet long, so we’d slide them into the passenger side window of my Plymouth Duster, so one end would rest under the car’s rear window, and the other end protruded out the window at an angle. Ok, not the best method of transport.

Dad, then an engineer at Chrysler, warned me to not drive faster than 30 mph, lest the wind catch the protruding aluminum and fold it back. I found all speed limits intrusive, especially a Dad-imposed one, because I was at peak-dumb age for men. We had to make several trips like this, and I kept my speed below 30 a few times, even though I thought the caution was excessive.

Then I decided to go 35, which I was sure the panels could handle. I figured I could accelerate very slowly and Dad wouldn’t notice. Then I’d tell Dad we were doing 35, and he’d have to admit that I know everything.

The aluminum folded up at 31 f***ing miles per hour. Dad was angry because money, and because I hadn’t listened. I was angry at me, at the aluminum, and at him, for being so correct about how much speed that aluminum could handle.

This was ~15 years ago at a Mack Truck plant (owned by Volvo). I was working on automated equipment and put the (Volvo issued) laptop I was using down on a control cabinet next to a hydraulic lift, hanging over the edge a few inches. Then I started the equipment, the lift began to lower and the protection for the cable/hydraulic raceway over the lift came down directly on the laptop. The laptop was simultaneously ripped in half and thrown across the room.

I was issued a new laptop and I was surprised to talk to my boss later and find nobody had mentioned it to him.

I worked at a grocery store, and once used a box cutter to cut through a box of large plastic bottles of laundry detergent. I cut through three of the bottles, and it’s hard to mop that up. This was the night shift, so I was able to go find the person running the floor cleaning machine. I did the same thing with olive oil months later.