I discovered this for myself when I realized that while on 4 hours of sleep, I could power through stuff with the aid of enough caffeine and feel at least margi

I discovered this for myself when I realized that while on 4 hours of sleep, I could power through stuff with the aid of enough caffeine and feel at least marginally productive... ...but I started leaving typos in everything. That really doesn't sound like much, right? Honestly, though, it genuinely freaked me out a little, existentially, the first time I noticed. I was one of those nerds who got to a state spelling bee as a kid, and I've always been a voracious reader. I've had spell-check turned off since forever because it would inevitably be the spell-check that was wrong about niche terms. But without enough sleep, all of that competence that I usually just take for granted vanishes. I end up with 'good moerning' and 'how are yoiu' and 'paass the salt', and I don't even notice I'm doing it until I look back at what I've written and double-take. And that's just with casual writing, probably one of the lowest-overhead mental tasks possible for many people. God only knows what kind of disaster would result from me trying to drive or operate heavy machinery in that state.