In his dreams he found a princess in a far away land.
She told him it was a dream and he was asleep in class.
"A dream," said the princess, "is a series of thoughts, images, and sensations occurring in a person's mind during sleep."
His dream changed, and he ended up in front of an opera house. A man and a woman there told him that since he was dreaming, he was in the REM sleep stage, or Rapid Eye Movement stage. This stage is when people dream.
They told him that he must've been asleep for a while because he had to have gotten through the awake stage, the light sleep stage, and the deep sleep stage to get to REM.
"You should probably get more sleep," said Death. "If you don't sleep enough you'll end up falling asleep in class. But be careful not to sleep too much. That will also make you feel tired."