university study over a decade ago (Université de Liège in Belgium) compared levels of alertness between “early birds” and “night owls” – 10 hours after waking, night owls stayed more alert (early birds peaked faster, night owls had stamina) – best idea at the time was guessing some leftover from when a few of the tribe took night’s watch …

Who are and then there slightly more are night people, productive at, like me, night.