Ed walks up as Shawn's jogging away. He goes to hug Carol and she sobs in his arms, knowing now that she really, REALLY screwed up a kid's life. Ed asks her if she's ever tried a peanut butter and bacon sandwich. She says, "No." He softly says, "Come with me," and the show ends as they walk away.
The moral of the story? If you're an adult and stuck in a dead-end job that you absolutely hate...blame a teacher.