> Think about sleep 10,000 years ago. You sleep in a cave, in a hut, or under the sky, with predators and enemy tribes roaming around. You are on a wooden floor, on an animal’s skin, or on the ground.
I would argue that some of my best nights were during outdoor survival situations where I slept in small shelters that kept my warmth and on a hard surface.
Personally, the sound of a familiar bird species will lull me to sleep. Birds sing when it's safe. Silence in nature is when you should worry.
Having slept on bear skins, those are surprisingly comfortable. That's why it's such a trope in romance. You can easily fall asleep on one and be comfortable all night. Throw in a few friends and you have got a cozy experience. Three people will keep a bed very warm even without heating to the point where you must open windows and get rid of covers.
Have we forgotten that our species has used fire as a tool for at least 2 million years? Usually, a fire would be kept going all night which would keep the camping ground dry and warm.
Has the author ever slept in the wild? Birds waking you? If this held true, no one would be able to sleep in rural areas.
This thesis seems to extrapolate a lot without paying attention to the details. It presents ideas as common sense and proceeds to mislead the reader through cherry-picked information that is a prime example of the confirmation bias.