As long as we're owning up to doing dumb stuff...
Ever try to take apart a suspension on a car without using a spring compressor? Lots of energy in those bastards.. this particular one shot through the strut tower, through the hood, through the tin shop roof, and was eventually found a couple of hundred feet to the west in an adjacent field. Worst part? We knew better and the compressor was on the bench 10 ft away..
Or the time I was welding patches on the floor on the driver's side of my beater at the time. Completely forgetting there was insulation and carpet on the other side. Never bothered to replace the carpet and the car never smelled right after that. Again, I should've known better.
Same beater car, 2 months later - hooking up two sets of booster cables end to end to make it reach, only to realize a short while later both sets of clips in the middle were touching despite the attempt to keep them seperated. Melted the insulation off one of the sets of cables all over my engine compartment and fried the electrical system in my car.. thankfully not my friend's. Next call was to the wreckers to come pick it up. I'd had enough, and besides, the interior stunk of stale smoke.
All things that *seemed* like a good idea at the time..
While I like to think I'm past the age of doing something retarded and that I now think things through, I fully anticipate holing my own boat in some stupid manner at some point.. And at least now I'll know how to deal with it. Huzzah for plungers!