re: Why is Ferris Bueller's Day Off considered so great?

It's pretty much what it comes down to. The same can be said for a lot of children's movies too. There's a lot of wonderment and novelty that is lost. Most adults probably aren't going to really get into something like The Dark Crystal as adults without the sense of nostalgia.

Ferris Beuller is great because it's a movie about getting over yourself and just having fun. It's a pretty solid idea for a teenager. Also, Ferris is cool as shite.