1. When you have a sinus infection
  2. When you're sad
  3. When you're getting your period
  4. When you had disruptive sleep
  5. When you can't remember if you did or did not take your vitamins last night.
  6. When you wake up to go to the airport and it's still dark out
  7. The Friday before a holiday weekend and you have a deadline
  8. The last night of a 3 day weekend