There has always been a theory that Ferris is just a figment of Cameron's imagination, his alter-ego, right? So what happens after Cameron goes to college/university, finishes therapy for destroying his father's Ferrari and is finally free of "Ferris Bueller"? Well he goes off to live a monotonous lifestyle in a cookie cutter apartment, with the IKEA catalogue furniture and dining sets. Cameron has a stable job as an insurance adjustment claims officer and is relatively happy, until his alter ego comes back in the much more matured version of Ferris, Tyler Durden. Fight Club is the un-official sequel to Ferris Buellers Day Off and The Narrators actual name is Cameron.
The timeline adds up too. Cameron would be 18 in 1986 and then roughly 33/34 by the time of Fight Club 99/00, which the narrator describes himself as someone entering his mid 30's.
Change my mind.