It's funny to get older and finally learn lessons that have been drilled into me since I was old enough to listen; but that's life.

Sleep is very, very important. It determines baseline more than any other factor. Good sleep creates the possibility for a good day. Poor sleep almost guarantees a bad or at least difficult day.

Bryan Johnson, the nighttime erections guy, says:

Make sleep your #1 priority. Nothing influences your conscious existence more.

He's right. I don't agree with him on everything though.

For a long time I kept my room cold for sleeping - around 67-69 F - and that helped my sleep. Any warmer and I'd wake up hot. At some point I switched from a duvet filled with synthetic insulation to a weighted duvet filled with glass beads. I also moved to a newer place with more efficient cooling, keeping the temperature closer to its actual setting - so, cooler than my previous place.

After a while of not sleeping very well, I tried bumping the temperature up a few degrees. Almost instantly my sleep quality improved:

1. Sleeping HRV improved overnight. On the best nights I was reading ~40ms. After increasing the temp, I am regularly reading over 60ms.
2. Sleep quality as measured by my sleep tracker improved by around 20%

I am not sure how long this has been affecting my sleep but at minimum it was 6 months.