1. A glimmer of sunlight has peeked over the horizon.
  2. Someone is operating a leaf blower/lawnmower outside.
  3. One particular stuffy friend is just out of sight and/or reach.
  4. Slightly woke up but still very very tired and should be sleeping but can't fall back to sleep.
  5. Latest reason (and new personal favorite) at dark o'clock in the morning: "Me need cookies!"
    This was a straight-up craving. He doesn't even know who Cookie Monster is.