Comment by PeterStuer

Tangentially: as a 'young adult' I was a typical 'night owl'. Cognitivly I peaked between 10pm and 3am, typically slept from 4am to 11am. When I got kids and a more 'regular' job, I was forced to change to a more normal schedule. The transition from 'owl' to 'lark' was not easy. It took about 7 years. These days, I peak 7am to 1pm.