Important to note there has been pushback on Matthew Walker's writing. Feel free to read more from Alexey Guzey [1] or Andrew Gelman [2].
[1]https://guzey.com/books/why-we-sleep/ [2]https://statmodeling.stat.columbia.edu/2020/03/24/why-we-sle...
[1]https://guzey.com/books/why-we-sleep/ [2]https://statmodeling.stat.columbia.edu/2020/03/24/why-we-sle...