When Denzel Washington said he took the role in Roman J. Israel, Esq. to improve as an actor, I thought he was kidding.

But the two-time Oscar winner insisted that playing Roman — a neurodiverse, on-the-spectrum attorney — gave him the kind of career challenge he needs to stay sharp.

"I'm trying to get better," said Washington,  who was nominated last year for another Oscar. He heard my incredulous laugh. "No, I'm serious. When I turned 60 and started to think about my career differently, I'm like — this ain't dress rehearsal. I really don't know how many years I have left on this planet, so I just want to maximize the effort and utilize the gifts I've been given."

The part came to him from writer-director Dan Gilroy (Nightcrawler), who wrote it with Washington in mind.

"I came off Nightcrawler and I spent eight months writing this script, and I wasn't paid to write it. I wrote it for Denzel, though I had never met him before," Gilroy said.

Why?

"I've been obsessed with Denzel forever. I think he's the greatest actor in the world, and I've always wanted to work with him. When I heard he was interested, I flew to New York and had a three-hour lunch with him, and he shook my hand and said, I want to do this with you," he said. "Because he's never played a character like this before. So many of his characters are alpha males and very together and strong."

Roman is a lawyer with a brilliant mind, an encyclopedic knowledge of case law, a rigid sense of right and wrong, and a grounding in the civil rights movement. But he has a hard time dealing with people, so the managing partner of his firm uses him strictly for research. When that partner dies, Roman is thrust into the courtroom, and into life, in ways that are fraught for Roman, his clients, and his colleagues (including Colin Farrell).

Washington said finding a road map to Roman wasn't hard.

"We all know people like Roman. Through friends or family. I have a good friend whose son is on the spectrum and works in a law firm, in a capacity similar to Roman. A guy who knows the law inside and out but sometimes can't remember how to get home at night, or can't handle people, has a hard time making eye contact. The thing about Roman is he can read any book with total recall, but he can't read people. That is really fascinating to play. You want to get the behavior right, but you also want to do it with empathy, to bring the proper humanity to the role."

Washington tends to get very specific with characters — Gilroy said the actor designed his own clothes for the role — a collection of wide-lapel late-1970s jackets and large-frame glasses that show Washington at his most unglamorous.

When pictures of the actor working on location surfaced on the internet, some of the trolling was illuminating.

"I'm just an actor playing a character. But you're reading these comments and you're thinking, 'Wow, so that's how it is.' You get just a glimpse, just a taste of what people like Roman have to live with every day. It was instructive."

Washington has other personal connections to the material.

"My sister has bipolar disorder. And I know that what she has and what Roman has are very different, but I've been looking for a long time for something that would allow me to go at least in that direction. I felt an extra incentive to the best job I could with the character. I think that when we can all form a fuller understanding of other human beings, we can do a better job of treating them as full human beings," he said.

Gilroy said Washington also connected with Roman's sense of principle.

"Denzel is a man of faith. And I knew that about him. Denzel talks about his faith all the time. He's a man of God, first and last. Roman is all about justice — he believes in things. And it's very difficult to find an actor today who can make that credible," he said.

In the end, Washington said he fell pretty hard for Roman.

"We overlook people like Roman, It's easy for them to fall through the cracks of society. And maybe for that reason, I can tell you I love this guy more than any other character I've played in my life," said Washington, who's won Oscars for Training Day and Glory, and who has been nominated a total of seven times.

"You have to love the guy. He's trying. He's just alone."