Supernatural (TV series)/Recap/S04/E13 After School Special

Season 4, Episode 13:

After School Special
Sam and Dean discover that a spirit is haunting one of their old high schools. While investigating the haunting Dean and Sam relive their high school experiences through flashbacks recalling how Sam was picked on by the school bully while Dean was Mr. Popular. They discover that the spirit was a former classmate of Sam's who he thought was a bully. In reality, it was the bully who had been tormented by jocks and has come back to seek revenge on those who pick on the nerds.

Tropes

 * Badass Adorable: Despite his size and Woobie status, young Sam can really handle himself in a fight.
 * Groin Attack: The ghost takes this approach with Sam.
 * Legal Jailbait: "Three of the cheerleaders are legal. Guess which ones."
 * Older Than They Look: The actor playing young Sam looks way too young to be in high school.
 * Fridge Brilliance: Sam could have skipped a grade or two given how intelligent he is.
 * Papa Bear: Dean's reaction when he founds out that Sam got punched.
 * Writers Cannot Do Math: Dean is four years older than Sam, so they never would have been in high school together.
 * See Fridge Brilliance above. Also, Dean could quite possibly have repeated a year or two - he's quite clever, but moving schools several times in a year does not generally help one's academic performance.