The gimmick of the Forrest Gump movie is two fold. Mr "Everyman" Forrest is pasted into every major historical event the audience of that time was likely to remember. That movie was some time ago so Gump had little to do with computers other then buying stock in Apple.
The other gimmick is that Gump is suppose to be just a humble simple everyman who had no idea the massive impact he is having on humanity around him.
Time and time again things happen in Gump because the people around him want it to happen, or via a kind of magic, with Gump himself utterly unaware of the social meaning.
So the speech about Vietnam, where he is faced with a mass of contradicting instincts and political agendas, has to be empty. Its just impossible for the American people to reconcile Vietnam, at that time before Iraq gave them fresh wounds to lick, and so Gump silence presents a magic resolution, everyone in the audience can imagine the statement they need about Vietnam has happened.
Frankly I found this very disturbing, the worship of mass media culture in to some 'meaningful' event, combined with a naive worship of the wisdom of idiots was a uniquely American hubris, one I think the US paid a very heavy price for in the years after this 1990s feel good film was released.
A nation who can see Gump as a source of social stability, wealth and reason is a nation that elects George W. Bush.