I'm looking for a specific fic (almost certainly AO3) in which Sam and Dean are retired from hunting, and they teach seminars to other hunters in the MoL bunker. I remember one of them was struggling to come up with a subject to specialise in, and eventually decided on the Winchesters' own history, and was then surprised that a lot of people turned up to listen. I'm pretty sure Jody Mills and Claire Novak and that gang were in it, but I doubt they'd have been tagged as characters.

Pairing would be either gen or Destiel, NOT Wincest.

Any help greatly appreciated!!