Although Daniel Day-Lewis had announced years ago that he intended to retire from acting, the Oscar-winning actor has stepped back onto the set — this time for his son. He explained that refusing to collaborate with Ronan on his first film would have been a much worse mistake.

Father and son appeared together at the world premiere of Anemone at the New York Film Festival on Sunday, September 28.

“I looked foolish saying I would stop working, and probably even more foolish coming back,” Day-Lewis told PEOPLE. “But denying myself the chance to work with Ronan just to preserve my pride would have been a worse decision than simply admitting, ‘I said it, but I’m moving past it.’”

For his first acting role in eight years, Day-Lewis found himself being directed by his own son — though, he admitted, there wasn’t much time to dwell on that fact.

The 68-year-old actor noted that their family ties didn’t weigh heavily on him during the production. When asked if it felt strange to be directed by his 27-year-old son, Day-Lewis — who retired in 2017 — replied:

“If I had stepped back and looked at it that way, yes, I probably would have walked off the set immediately. Luckily, we were both so absorbed in the work, in the story we were trying to tell.”

He added: “There were days on set when we looked at each other and couldn’t quite believe we were actually doing this, but beyond that we just kept moving forward. Thankfully, there wasn’t time to overthink it.”

Anemone not only marks Day-Lewis’s return to acting after an eight-year break but also Ronan’s debut as both screenwriter and director.

Actor Sean Bean, who co-stars in the film, told PEOPLE he felt like he was part of a family project: “They were both incredibly welcoming,” he said.