I would imagine our hunter gatherer ancestors had a far easier time falling asleep given their activity level during the day, their diet, and their lack of artificial lighting (particularly blue light).

Actual insomnia has been documented forever, it’s something going wrong, but I do think struggling to sleep in general is our modern lifestyles. Back in my grandads day the majority of people got up early, went out to work hard physical jobs, came home exhausted, had dinner and maybe a bit of family time, then in bed by 9pm. Women at the time often stayed at home but that involved a lot more physical work than we do these days, you’d wash the clothes by hand, heat up the water in a pot for washing up, always busy.

Modern life is brilliant, we have more time to do stuff we enjoy, but we’re just not that physically challenged.

I remember from the book “Why We Sleep” that our sleep cycle takes cues from both light and temperature levels throughout the day, which we isolated ourselves from in modern times. The day doesn’t end after sundown anymore thanks to lightbulbs, and many of us live at a constant temperature due to AC. That’s two clues of “night is near, prep to sleep” that we no longer receive. Maybe our ancestors had an easier time due to more consistent clues?

Years I I remember reading something about it as an evolutionary necessity. I have no reference now. Anyway it says that having in a tribe people accustomed to fall asleep at different times and in different condition allowed to have always at least one person on a watch for dangers coming from the outside. This does nor explain why people struggle to fall asleep for long hours, but at least it gives a partial explanation.

We can’t? I’ve never had a problem. I simply lay down and turn my brain off. Asleep within 5 minutes.

I’d love to be able to sleep on command.

Usually I need to take a melatonin pill after tossing and turning before I get some sleep.