1. How angry you are that you had a lot of sugar and caffeine
  2. How bad your day will be tomorrow
  3. Death
  4. Denial of death
  5. The possibility you will never sleep again
  6. The eventual end of the universe
  7. What was around before the universe
  8. Madness
  9. Whether you should get up to use the bathroom
  10. Itchy areas
  11. Sudden unexplained body pains
  12. The increasing heat of your head and pillow
  13. Whether everyone secretly hates you
  14. Whether or not you actually hate everyone
  15. Disease
  16. Whether you'll become so tired that you sleep through a fire or gas leak
  17. Why it seems so easy for other animals to sleep
  18. Why it's so difficult to sleep on your back
  19. Why pregnant woman aren't in a constant state of fear and anxiety
  20. Why there is so much good music but so few good movies
  21. Everything you could have done better
  22. Thoughtless things you may have said the previous day
  23. Wasted oppurtunities
  24. Whether your breathing sounds wrong
  25. How being stabbed or shot might feel
  26. Whether you should try sleeping on the floor or outside in the yard
  27. Is the voice in your head your own?