In life, as the famous saying goes, you never know what you're gonna get.

But when it comes to a possible sequel to the Oscar-winning film Forrest Gump, we now at least have some idea.

There was going to be a follow-up to the Best Picture winner, released in 1994, and it was going to be just as chock-full with historical references as the original.

But the film never went ahead, initially because of the mood among its creators following the September 11 terrorist attacks, according the film's screenwriter, Eric Roth.

Tom Hanks won the Best Actor Oscar for his performance. ( Facebook )

"Literally, I turned [a draft script] in the day before 9/11," Roth said in an interview with Yahoo published on Thursday.

"And Tom [Hanks] and I and Bob [director Robert Zemeckis] got together on 9/11 to sort of commiserate about how life was in America and how tragic it was. And we looked at each other and said 'this movie has no meaning anymore' in that sense."

The original film, which won six Academy Awards, including Best Actor for Hanks, is a much-loved piece of 1990s cinema. The humour that came through the real-life tie-ins was one of its hallmarks.

So, what kind of stuff would the loveable Alabaman have gotten up to had the sequel been made?

Forrest may have dealt with his son's illness

The original film ends with Forrest waving goodbye as his son, Forrest Jnr, whose mother was Forrest's lifelong love Jenny, gets on the school bus.

Jenny died in the first film, succumbing to an illness that was never fully explored but was assumed to be HIV/AIDS.

Forrest's son, Forrest Gump Jnr (Haley Joel Osment), appears at the end of the original film. ( Facebook )

"It was going to start with his little boy having AIDS," Roth said.

"And people wouldn't go to class with him in Florida.

"We had a funny sequence where they were busing [to desegregate schools] in Florida at the same time, so people were angry about either the busing, or [their] kids having to go to school with the kid who had AIDS. So, there was a big conflict."

Busing, which was used to make schools more racially diverse after segregation officially ended, was still a controversial thing in the 1980s.

Forrest has run-ins with OJ Simpson and Princess Diana

"I had him in the back of OJ's Bronco," Roth said of Forrest, referring to the truck accused double murderer Simpson used to escape police in 1994. The California highway chase was broadcast live.

"He would look up occasionally, but they didn't see him in the rear-view mirror, and then he'd pop down."

Forrest joined the Army and was decorated for his bravery in Vietnam. ( Facebook )

In the original film, Forrest takes up ping pong, to great acclaim — he lands a spot on the national team (leading to his third meeting with a US president), gets interviewed on national TV alongside John Lennon, and scores an endorsement deal with a paddle maker.

In the sequel, he would have found similar success as a dancer.

"I had him as a ballroom dancer who was really good," Roth said.

"And then eventually, just as sort of a charity kind of thing, he danced with Princess Diana."

The Oklahoma City bombing would have featured

In the draft script, Forrest finds his "calling", Roth said, calling bingo numbers on a Native American reservation.

"And the big event in that, which you could see was diminished only in tragedy, I guess, because it's the same tragedy, [was] every day he'd go wait for his Native American partner.

Eric Roth won an Oscar for Best Adapted Screenplay for his work on Forrest Gump. ( Reuters: Blake Sell )

"She taught nursery school at a government building in Oklahoma City.

"And he was sitting on the bench waiting for her to have lunch and all of a sudden the building behind him blows up."

The Oklahoma City bombing, in 1995, is the deadliest domestic terrorist attack in US history, killing 168 people. Bomber Timothy McVeigh, who was later executed, said he was motivated by his dislike of the federal government.

In the interview, Roth suggested that scene, given it involved terrorism, was a catalyst for the sequel being scrapped, though the idea of the film itself may have soured for the trio in the immediate aftermath of 9/11.

"When 9/11 occurred I think we felt, maybe, everything we'd written was meaningless," he said.

There have been reports in the past about a possible second film.

In 2007, author Winston Groom, on whose book the original film is based, said Paramount Pictures had also bought the rights to Gump & Co, Groom's follow-up novel.

He told the website Cinema Blend: "They then owned it, as they still do, and can make it a movie anytime they damn well please."