What stupid injury left a long lasting impact on you?

Bent down to pick up a kitten in my garage when I was 8. It was under a car engine suspended on a lift, and I brained myself badly while standing up. Lots of blood, seizures due to three TBI and resultant swelling. Thankfully my mother bravely stood up to the mean old doctor insisting I needed surgery to relieve the swelling and instead treated me with psychic healing and veggie smoothies. It only hurts sometimes 45 years later.

Bent down to pick up a box while cleaning an extra bedroom that had become infested with bees (they had started a hive in the wall due to an unseen opening happened around a hot water pipe after an earthquake). Frustrated due to both the intense heat and the bees that had only left their hive due to said heat, tried lifting said box, not realizing it was full of books and simultaneously ignoring a lifetime of working around my chronic back issues. I stopped trying to stand once I resembled a fleshy right angle and had to crawl out of the room on my hands and knees. A lovely 40 mph fender bender later that year (I was at a complete stop as were the cars in front of me) made that a delightful addition to my back problems.

Same year, I was making Hasselback potatoes for the first time. I have a seldom used but quite nice food processor, but decided 'hell, why not use the mandolin?' About an 1/8" of my right ring fingertip, that's why not, dumbass! Thankfully it grew back, but the very tip looks like a light burn scar and it's still somewhat numb and tingly when touched 9 years later.