The Skull Score: Sleep Basics for Less Bad Days and More Good Decades

I flipped from night shifts to days for my kids’ soccer and school events and felt “fine”… until my wearable gave me a literal skull recovery score. That screenshot did what no lecture ever did: it made sleep feel urgent.In this episode, we cover Sleep Basics — what sleep is (NREM/REM cycles), how it’s regulated (sleep pressure + circadian rhythm), and how melatonin, cortisol, light exposure, meal timing, temperature, activity, social schedules, and alcohol shape sleep quality. Then we take a quick world tour of large cohort studies (UK Biobank, MESA, Whitehall II, China Kadoorie Biobank and more), break down a practical “Core Four” circadian habit framework, and finish with an 80/20 Tier 1 sleep plan you can start tonight.We’ll also tee up a later episode that goes deep on shift-work sleep — because nights are a different game with different rules.Educational only — not medical advice. If you have symptoms of a sleep disorder (e.g., loud snoring, witnessed apneas, severe daytime sleepiness), please seek care from a qualified clinician.