A lot of scientific and medical literature disagrees with you. You also assume a lot about their habits and what they've tried. Studies of chronotype consisten

A lot of scientific and medical literature disagrees with you. You also assume a lot about their habits and what they've tried. Studies of chronotype consistently show a near-normal distribution skewed toward later hours.[1] This is partly heritable.[2] Genetic studies have found markers for chronotype near genes known to affect circadian rhythm.[3] Delayed sleep phase disorder may be a distinct condition or just the tail of the chronotype distribution. Either way, it exists. It usually responds to treatment, but relapse rates are over 90%.[4] The world isn't asleep by 9:00 every night. Even a day in bed sick can cause a relapse. "Rolling forward" may increase the risk of non-24-hour sleep disorder in people who have DSPD.[5] [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5479630/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5479630/ [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4363835/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4363835/ [3] https://news.ycombinator.com/item?id=18760498 https://news.ycombinator.com/item?id=18760498 [4] https://www.ncbi.nlm.nih.gov/pubmed/9562922 https://www.ncbi.nlm.nih.gov/pubmed/9562922 [5] https://www.circadiansleepdisorders.org/info/N24chrono.php https://www.circadiansleepdisorders.org/info/N24chrono.php