Forrest Gump might look like your typical sentimental drama from the mid-'90s. And, in a way, it is. But, you might not have noticed that this movie was using some pretty sophisticated special effects for its time. Long before Kim Kardashian was Photoshopping her Instagram pictures, this movie used computer techniques to Photoshop Forrest into major historical footage. Look, for example, at the scene where Forrest meets President John F. Kennedy, a man who died when actor Tom Hanks was only 7 years old.
You'll find another great use of this in the way the movie Photoshops Lt. Dan's (or actor Gary Sinise's) legs out of the film after Lt. Dan has his legs blown off.