I'll confess I'm very skeptical of this account, as a former Marine who has also experienced mild hallucinations on deployment and a registered polysomnographic technologist. (I don't interpret sleep studies as a career anymore, but I'm familiar with the literature and have published some modest research. While it has been some years, I also did a bit over a thousand sleep studies.)

First off: sleep is highly, highly, highly evolutionarily conserved. Essentially every complex lifeform with an active metabolism either sleeps or it does something that resembles sleep. Sleep as a practice is never lost via mutation or other evolutionary change.

There are zero examples of a speciation causing an organism that sleeps to stop doing so, and zero examples of an organism that doesn't sleep that has a common ancestor who does. ("Sleep" is broadly interpreted.)

It's difficult to describe just iron this rule is. Sleep shares this with just a handful of other systems, largely consisting of fetal development genes and other systems in which a single genetic change kills the organism.

And, in our experience, that's because going without sleep also kills the organism. In humans, the one example we know of that causes total inability to sleep is Fatal Familial Insomnia, a genetic prion disorder with 100% mortality.

Second, people are very, very, very bad at assessing whether they have been asleep. I cannot tell you the number of people I have seen who were asleep-- verifiably asleep, because I was watching their brain waves in real-time-- who, when woken for some reason or another, report they never fell asleep. I've seen people sleep the entire night and claim they didn't sleep a wink.

Third, people who are sleep deprived cannot accurately assess their acute impairment, and this is worse with chronic deprivation, not only because of worsened cognitive function but because the person no longer has a healthy baseline in recent memory to compare to.

People assess whether they're functioning well by comparison to yesterday and last week and this month. If they were sleep deprived then as well, they report the differences between that time and now, if any, NOT the actual absolute value of their impairment.

Fourth, and finally, the causative correlations between sleep deprivation and impairment are super robust. The parent article is describing people who are less affected, but still experience profound impairment. It just happens that their impairment is small relative to others. While so-called "short sleepers"-- the actual technical term for the healthy 6 hours a nighters-- do in fact seem to do find with somewhat less sleep, they also experience impairment when getting less than their normal sleep time.

Obviously, I can't verify for certain that our parent comment is mistaken in their perception.

But what I can say quite comfortably is that if what they say is true, they are a walking Nobel Prize. What they describe is not considered unlikely, it's considered fundamentally impossible.

Mind, it wouldn't be the first time distinguished scientists advised us if was impossible, and turned out to be wrong, but this would really be closer to the scale of "general relativity is wrong" rather than "oops, eggs are good for you.

Parent commenter: if you read this, and if you genuinely believe your experience is as described, please contact William Dement, "Bill" Dement, at Stanford University...ASAP!

He is the grandfather of sleep medicine and conducted the first scientific sleep studies in the world. I can say with total confidence that if what you say is correct, he will either drop what he is researching and study you, or find a researcher who can. And if what you say is true you owe it to the world and posterity to be studied.