This whole its all in his head is just the wrong direction ferris bueller is cameron fry , cameron fry is ferris bueller, although ferris family is entirely fake. ferris bueller impact on the community is real only its cameron fry they all love and adore. sloane loves cameron who is ferris only cameron doesn’t know he is ferris bueller. Nothing about his day off was fake execpt there was only two people on that trip, fry and sloane.
So everything public done by ferris was done by cameron.

This theory is stupid. It’s just taking what is already symbolically there in the movie, and pretending it’s literal. Also, if Ferris isn’t real, why is there a B plot about his (also not real?) sister?

I mean. Ferris is an unrealistic character grounded by several realistic characters, he’s the kind of person everyone wishes they could be: Someone who doesn’t let life pass them by. And it’s about Cameron, a more everyman-type person, learning from his exaggeratedly more has-it-all-figured-out friend. And everyone feels like they know someone like that, because “having it all figured out” is relative; you feel lost and your friends seem to have it all together, but the reverse is also true for them. In that sense Ferris is the fantasy element of the movie, but in the reality of the film, he’s a flesh-and-blood human being.

Don’t forget the Calvin & Hobbes Fight Club Theory from a while back.

Here’s an interesting counter to that idea from the Slashfilm.com message boards (from user eightcell): http://www.slashfilm.com/2009/04/30/the-ferris-bueller-fight-club-theory/ I think this theory can be applied to almost anything. Examples: Let’s say that Obi Wan Kenobi was a figment of Luke’s imagination in Star Wars
. After having his first real adventure away from home he doesn’t need him anymore and he imagines Darth Vader killing him. Obi Wan only shows up when he is in his most defeated states from then on, and Luke has to justify this my imagining Obi Wan as a ghost. Indiana Jones never went on any crazy adventures, they were all in the head of this boring college instructor, which is why he never has anything to show for it at the end. Kermit is the only real Muppet. Everyone else - Fozzy, Gonzo, Piggy are all splinters of his personality which he see’s because he has been mistreated by society for so long and felt so alone for being a giant talking frog. Roger Murtaugh has been on the straight and narrow for so long and one day he snaps, imagining a crazy new partner for himself named Martin Riggs. Riggs seems to have no fear and doesn’t play by the book. You could reverse it too. Drop Dead Fred was a real. Tyler Durden was real, the narrator just snapped and convinced himself that Tyler wasn’t because of the envy he had built up. It’s funny to think of a movie liek this way, from a differnt POV - but this “logic” can be applied to anything as long as you ignore or don’t accept anything that contradicts your theory. You see the way it goes down on film, unless it’s left intentionally “vague” (Pan’s Labyrinth, Contact) the way you saw it on screen is the way it happened.