Trump said he won’t watch the new Neil Armstrong movie. Here’s why the cast and crew say you should.

It’s an age-old adage: Don’t knock it ‘til you try it.

Or in the case of the new film “First Man,” don’t knock it ‘til you watch it, its cast and crew say.

The hoopla that inevitably accompanies the build-up to a blockbuster debut took a surprisingly political turn for the new Damien Chazelle-directed film “First Man,” which focuses on Neil Armstrong’s journey to become the first human to set foot on the lunar surface. The point of contention lies not in what’s portrayed, but rather what’s left out – the act of planting the U.S. flag on the moon upon the astronauts’ arrival, the omission of which has led many, from Sen. Marco Rubio, R-Fla., to President Donald Trump, to criticize the film.

“The American people paid for that mission, on rockets built by Americans, with American technology & carrying American astronauts,” Rubio wrote in an Aug. 31 tweet.

Trump called the omission a “terrible thing” in an interview with the Daily Caller.

“When you think of Neil Armstrong and when you think about the landing on the moon, you think about the American flag,” he said. “So for that reason, I wouldn’t even want to watch the movie.”

At the D.C. premiere of “First Man,” held Thursday night at the Air and Space Museum, the movie’s filmmakers and stars said that the missing iconic imagery is exactly why you should see the movie. Ryan Gosling, who portrays Armstrong, and Claire Foy, who plays his wife Janet Shearon, posed for photos yet dodged reporters on the red carpet, but others defended the film.

“That moment people are talking about is iconic, but something Damien really wanted to try to do with this picture was tell the personal, intimate story of Neil Armstrong,” film editor David Cross said. “We figured that most people are familiar with Neil, the icon, so we really wanted to show Neil, the man.”

That meant deep-diving into Armstrong’s internal struggles, primarily centered on his family – the loss of his daughter, explaining to his two living sons that each new mission might mean their father would never come back. “We spend a lot more time on the family than I think people will be expecting,” screenwriter Josh Singer, who also wrote “The Post” and “Spotlight,” said.

James R. Hansen, author of the book “First Man: The Life of Neil A. Armstrong” on which the movie is based, explained that the film has a twofold journey that runs in parallel – the journey of the country and the lunar program to get to the moon, and the personal emotional journey of Armstrong.

The famous quotes, the flag planting – those are things people already know. Or at least think they know.

“People’s memory of the flag planting is also probably not very good,” Hansen said. “In truth, it took them over 10 minutes to get [the flag] in, because the surface was harder than they thought. So what people remember about it is the picture, which is really a picture of Buzz [Aldrin] next to the flag. There’s no picture of Neil next to the flag.” So an accurate depiction of the flag-planting sequence would be a 10-minute depiction of their trial-and-error, Hansen said.

Instead, the filmmakers chose to focus on what people didn’t see, mainly the private time Armstrong spent while he was up there – the only moment of the lunar landing that wasn’t scripted, according to Singer.

“The heroism of Neil Armstrong and all of the people that were a part of that effort to achieve the great thing that we did as a country, I think that kind of heroism is undeniable in the story that’s being told,” Brian d’Arcy James, who portrays astronaut Joseph A. Walker in the film, said.

People need to see the film for themselves, and they will probably be pleasantly surprised, said actor Shea Whigham, who plays astronaut Gus Grissom. “It’s an incredible piece of filmmaking,” he said. “When you have a generational talent like Damien Chazelle, you’re playing with house money. I can’t even explain how good he is.”