I didn’t suggest that you shouldn’t sleep enough, just that our feelings about how much we need to sleep might not be reliable, in either direction. Maybe we would benefit from sleeping even more than we do because we rarely are physically exhausted at the end of the day.

I do find that physical exercise and exhaustion are helpful for good sleep. If I lay down and "can't fall asleep", I typically get up and keep working until I can't help but fall asleep.