Continuity mistake: The lettering on the cake at the beginning changes after Stiffler messes it up. It's in a row then diagonal.
Character mistake: When Cadence meets the group at the airport and Finch comments "you're reading Descartes", she responds by utterly butchering the line "cogito, ergo sum." Odd that a student of Descartes would be unfamiliar with how to pronounce his most famous statement-somewhat analogous to a student of Einstein not knowing e=mc^2.
Answer: They never mentioned it, I think they just wanted us to assume that since it has been a few years they just lost touch with each other. Alot of people are no longer friends with poeple after college that they where friends with when college started.
pross79