1. Having an entire row to yourself on an airplane
  2. Meeting a new dog
  3. Couch naps
  4. Seeing your food arriving from across the room at a restaurant
  5. Being inside during a thunderstorm
  6. When a long line starts to form right as you're leaving
  7. Going to bed without setting an alarm for the next morning
  8. Walking through fresh snow
  9. Finding a bird's nest
  10. Getting in the car after a long day and seeing a beautiful sunset
    Suggested by @hannahbee
  11. Being outside during a thunderstorm.
    Suggested by @Andy9473