A simple-minded, kindhearted man enjoys a life of accidental success and fame when all he wants is to love the beautiful woman he has known since they were kids.

A special needs underdog with a heart of gold?affects the world with his goodness?while fighting?for the love of his childhood sweetheart

Good point about the brave dramatic choice.

I do believe that Forrest underwent a significant change throughout the story, and in his change inspired other characters around him to change as well.

He changed?from being the son of his parent?to the protector of his country and eventually to be the parent of his own child. He assumed the responsibility of parenthood as the last phase of his process of growth. Sure he staid naive and kindhearted, but he grew to become a responsible adult.

His inner journey wasn't conscious or intentional, rather a product of him and his environment. I believe that in the best of stories the inner journey of change occurs unbeknown to the main character.

But I don't think he has a particular ambition to become an adult. ?He ages physically, of course , but not mentally, nor emotionally. ? ?The world changes around him -- but he doesn't. ?His character is constant; he is always a naive, kindhearted person who is always in love with Jenny.

It seems to me the story works anyway because Forrest's lack of an objective goal is not accidental, not a failure of imagination or a failure to understand dramatic essentials. ?His lack of an objective goal is intentional and it takes a skilled writer to make that dramatic choice work. ?And Eric Roth, who scripted the story for the screen, is one of the best; he won the Oscar for his adaptation.