When Riker gets told he's half related, he doesn't believe it. It was just an April Fools prank. But then he starts noticing a lot of differences between him and his sibings...
Ravenclaws having an existential crisis. Slytherins just now realizing that everything they thought they knew is false. Hufflepuffs "trying" to stay out of everyone's way. And Gryffindor, they are just trying not to bust a gut.