First one isn't technically a mistake, but the outcome was...as a very young lad in rural Ohio, my best friend decided to try out his new rifle by shooting at those funny-looking cans on the poles...two shots and we were "rewarded" with the most evil sound heard by a kid and a nice bright explosion!! His father was "rewarded" by the local POCO with a repair bill of around $6,000 (This was around 1970)!! My friend was rewarded with a sore bottom that lasted for a week. I got heck too since my dad figured that since I knew about electricity I should have stopped my friend. [Linked Image]

Mistakes on my part:

Damaged the busbars on my parent's Zinsco panel trying to seat the double pole breaker for the garage subpanel I installed. Put my best screwdriver on the terminal and smacked it with my hand, broke right through the side of the breaker. End result: Damaged breaker, vaporized screwdriver, one scared old man.

Miswired an old, obsolete cinema projector console, causing total meltdown of the factory wiring. Rewired it my way and no problems!! (The maker of that console was known for serious quslity problems anyway.)

Working for a local electrician, had a meter socket (resi) fail when pulling the meter for a service change. The blast blew the meter out of my hands and across the lawn. I was VERY lucky as I was NOT wearing any PPE (the sunglasses I had on don't count.) Since then, I have always worn at a minimum rated gloves and faceshield and non-synthetic shirts. I would also cut the drop whenever possible before pulling meters.

Dollar wise the most expensive for me was knocking a coated glass reflector for a xenon lamphouse off the shelf while holding the bulb for same. Mirror $850.00 Bulb $1,250 Embarrasment on dropping both, priceless!!

A collegue recently dropped a $45,000 video projector while struggling to attach it to a lift. Ouch.

Stupid should be painful.