Watch his TED Talk: https://www.youtube.com/watch?v=5MuIMqhT8DM
Bill Gates on the book: https://www.gatesnotes.com/Books/Why-We-Sleep
Criticisms of the book: https://guzey.com/books/why-we-sleep/

• Lack of Sleep ages you 10 years by testosterone
• "Sleep Spindles" from Deep Sleep act like file transfer from short term memory to long term
• Sleep gets worse as you age
• Sleeping pills are blunt instruments - electrical stimulation helps better
• Daylight savings time causes 20% increase/decrease in heart attacks as we jump forward/backward due to lost sleep
• 70% loss in immunity with 4 hrs of sleep
• Nighttime shift work is carcinogen
• 711 genes distorted on 6 hrs of sleep
• Tips for better sleep:
  • no alcohol/caffeine
  • avoid naps during the day
  • regularity - bed and wake at same time regularly 
  • keep it cool: 18 deg celsius