NEW YORK — So how did he do it? What was it that allowed this rangy kid to spend five years posing as a Pan Am jet jockey (flanked by a self-procured bevy of beverage-cart-pushing beauties), a trial lawyer (having passed the Louisiana bar exam fair and square), and a resident at a big-city hospital — all while blanketing 50 states and countless foreign nations with a blizzard of bad checks? Yes, those were simpler, more trusting times. And the uniform didn’t hurt. And it’s clear that Frank Abagnale had quick, canny smarts, an eagle eye for detail, and brass-balled aplomb (something he rues now as callow recklessness). But more than anything, Abagnale was a natural performer.

So how does one act as an actor? In Manhattan’s Regency Hotel, Abagnale himself, now in his mid 50s and dressed in a smart navy suit with a handkerchief that matches his snow-white hair, recalls with amused admiration how DiCaprio prepped for his role as a role player.

"Leo walked up to me and said, ‘Mr. Abagnale, I was wondering if I could ask you a big favor. I wonder if you would consider coming and staying with me in my home for a couple of days. I’d like really to get to know a lot about you: what makes you tick, what you were thinking about when you were 16. I’d like to know your mannerisms, the way you walk, the way you talk. If I’m going to play your part, I’d like to do it the best I can, and I’d really appreciate if you’d do that.’

"So I went out and stayed with Leo. And every morning until evening he followed me around with a recorder and a notepad, and he literally never put down the recorder. It came on in the morning; it went off in the evening. Breakfast. Sitting in the living room. Sitting by the pool. Getting into the car. I had to laugh: I’d scratch my leg, and he’d go, ‘Why’d you do that?’ ‘Because I have an itch on my knee.’ ‘Do you do that all the time?’ ‘I don’t think I do . . . ’ "

Later that morning, I ask DiCaprio about the lessons he gleaned from his house guest. Sleepy-eyed and shower-wet, he clasps a cup of coffee. "The meetings that I had with Frank were so valuable because for the first time I really got a sense of how engaging this guy must have been. He would make you feel calm and at ease around him immediately, and you’d just feel immersed in what he was talking about. I would ask him, ‘Besides putting on these specific costumes, did you ever put on an accent? Y’know, did you ever try to become an actor?’ And he said, ‘No, no. I was always myself, I never changed who I was. I just studied the profession.’ So I said, ‘Well give me an example of you, say, talking to Pan Am.’ And all of a sudden, quite unconsciously, I think, he started slipping into this Southern drawl. I said, ‘Do you realize what you were just doing there?’ He’s like, ‘No, no, I don’t. What?’ It was instinctual on his part. Like a great actor, he had that gift. And he is a great actor. But his stage was the real world."

Has DiCaprio ever used his own talents for a similar swindle? "I get asked that question a lot. But no. Mr. Spielberg is the one who was a young con man. He used to go to the Universal lot when he was young and impersonate a producer or a director. He would go in and watch people edit television shows, direct television shows. He says that’s where he got a lot of his education. And he walked in for months, pretending to be someone that he wasn’t. I only tried to get out of math homework."

Spielberg himself later confirms this but avers that "I wasn’t anything like Frank Abagnale. I was shy, I was a mama’s boy. . . . I couldn’t have done any of the things Frank did. The closest I came was when I disguised myself as a junior executive and walked onto the Universal lot carrying a briefcase. That was the closest I ever came to doing an Abagnale."

And if the director swears that his deceptions stemmed from "a desperate need to be a moviemaker," he also can’t help admiring how young Frank put his acting acumen to use in the pursuit of filthy lucre. Spielberg chuckles as he thinks back on DiCaprio-as-Abagnale trying to pass off an early example of his shaky handiwork to a comely cashier. "It’s the sloppiest check you’ve ever seen," he marvels. "But he distracts the teller, and complements her eyes, and she just says, ‘How do you want this?’ "