An the end of the events of "The Sandman: The Dream Hunters", Morpheus is satisfied that events played out as they should have, and that everyone involved learned an important lesson.
Here is the text:
The raven confronts the lord of the Dreaming about this, as the story comes to a close. “What good did it do?” the raven asked.
“‘Lessons were learned,’ said the pale king. ‘Events occurred as it was proper for them to do. I do not perceive that my attention was wasted.’”
Probing deeper after that unsatisfactory reply, and additional exchanges between Dream and his winged charge, the Raven asks, pointedly, “And you also learn a lesson?”
But the pale king chose not to answer and remained wrapped in silence,...and after some time the raven flapped heavily away into the sky of dreams, and left the king entirely alone.”
What lesson did the Dream King learn here?
The raven, was he Matthew or some other raven?