This is one of my Fav films and seems a little forgotten now just how big it was...
There is some great Trivia about it on IMDB (link below) Its well worth a look e.g
Almost all of 'John Lennon' 's dialogue is from his song "Imagine" ("No possesions", "No religion too", "It's easy if you try...").
Bill Murray was considered for the role of Forrest
Gary Sinise's character tells Tom Hanks's character that the day Forrest works on a shrimp boat is the day he'd be an astronaut. This is a reference to the book, where Forrest actually becomes an astronaut,