Photo: Rob Gough/instagram

Bruce Willis and Rob Gough

Rob Goughis “honored and blessed” to have had the opportunity to work with Bruce Willis on what the world now knows is one of his final films.

While reflecting on spending time with the legendary actor after news broke of Willis’aphasiadiagnosis – a condition that affects one’s cognitive abilities – Gough opened up about filmingAmerican Siegein November with the award-winning actor.

“The guy is a legend and just so iconic,” Gough tells PEOPLE. “Even without this information [about his diagnosis], just to be on set with the guy was so memorable and so amazing for me. And then, learning about his condition, and that that was going to be one of his last films, I’m so honored and blessed that I got to work with the guy and learn from him.”

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“Even though he was going through this when he was on camera – it’s second nature to him, he just turned on, and you had no idea that anything was going on,” Gough continues, noting the way that Willis, 67, was “helpful to myself and helpful to others.”

“The advice that he would give people just on a whim to him was nothing but to others it was so profound.”

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Bruce Willis

Gough says as soon as the cameras rolled, Willis showed why he is a legend in the industry.

“Even though he may not be who he was 10 years ago, it was the small things, he saw things like inThe Matrix.”

Gough says when Willis was acting “you don’t know that he’s battling this that condition, he comes alive and, and delivers.”

“I’ve always thought of him as iconic, the GOAT, just the man. Knowing that he’s able to perform under what he’s going through, it just adds to that iconicness,” he adds.

Bruce Willis

Although Gough has fond memories of filming with Willis, some of his most treasured memories happened after the director yelled cut on scenes of the film, which was released in Janaury.

“You know, just the interaction when we weren’t filming, how he was so kind and sweet,” Gough tells PEOPLE of his biggest takeaway from spending time with theDie Hardactor.

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“We had talked about how he adores his family,” Gough says, adding that the pair talked about baseball cards – something theBillionaire Boys Clubactor collects. “He was just a nice guy, just a nice guy to hang with. He’s a sweetheart.”

Gough also tells PEOPLE he is forever thankful for the memories he shares with Willis: “To learn from another great [actor], even what he was going through, I still learned a tremendous amount from him. You are who you surround yourself with, so to learn from that guy who knows it better than anybody, even in his condition, he’s able to go out there and crush it. I’m super thankful. That’s for sure.”

RELATED VIDEO: Bruce Willis Has Aphasia and Is ‘Stepping Away’ from Acting, Family Reveals

On Wednesday, Willis' family shared the news of his diagnosis on social media, writingalongside a photo of himon their Instagram feeds, “To Bruce’s amazing supporters, as a family we wanted to share that our beloved Bruce has been experiencing some health issues and has recently been diagnosed with aphasia, which is impacting his cognitive abilities.”

“As a result of this and with much consideration,Bruce is stepping away from the careerthat has meant so much to him,” the caption added.

Bruce’s family’s Instagram posts went on to say that it “is a really challenging time” for them all, “and we are so appreciative of your continued love, compassion and support.”

“We are moving through this as a strong family unit, and wanted to bring his fans in because we know how much he means to you, as you do to him. As Bruce always says, ‘Live it up’ and together we plan to do just that,” they concluded, signing the note from the actor’s daughtersRumer Willis,Scout Willis,Tallulah Willis,Mabel WillisandEvelyn Willis, plus Bruce’s wifeEmma Heming Willisand his ex-wifeDemi Moore.

source: people.com