I mean, it's like, it's so arbitrary, James Potter almost killed Severus multiple times with his pranks, Sirius's prank is associated to James by association, so why is it that James, not even directly but indirectly, saves him from that werewolf dude, Severus owes him a life debt, what?
Also how come no one else has heard of this shit other than that one guy?
Also how come no one else has heard of this shit other than that one guy?