Never slept better getting older; I used to do 3-5 hour nights in my 20s because of stress for my company, sold the company and had no worries anymore so slept 8-9 hours/day. Opened another company but with far less worries (if it fails it’s sad but far from the existential stress the first company was) so now into my 50s I lay down, pass out and wake exactly 8 hours later. Usually remembering at least a few dreams.

I remember my granddad having the complete reverse; he slept well when younger (during WOII, which I would think is an actual existential threat vs monetary one) and when he was 50, he would take heavy sleeping pills and then even only get 4 hours or so.