In the world according to Nora Ephron — a world that seemed a very inviting place in some of the films she wrote (When Harry Met Sally, et. al.) and/or directed (You’ve Got Mail, Julie & Julia) — there are “guy movies,” and there are “chick movies.” She made no apology for specializing in the latter.

But Sleepless in Seattle, her very best film, remains as fresh and funny today as it did when it first hit theaters nearly 20 years ago, in large part because it kinda-sorta tweaks the conventions of romantic comedies — the quintessential chick flick genre — even as it fervently embraces them. A box-office smash back in the day, it continues to be one of the yardsticks by which other chick flicks are measured.

Ephron — who passed away Tuesday at age 71 — explained it all to me during a 1993 interview. A typical guy movie, she said, would be The Dirty Dozen, the sort of slam-bang, buddy-bonding melodrama where macho men are too busy dodging bullets and killing Nazis to talk about their inner feelings. (And, shucks, let's face it: You really wouldn't want to hear Lee Marvin or Charles Bronson discuss his inner feelings, would you?)

In sharp contrast, there is the archetypical chick movie: An Affair to Remember, the glossy romantic drama in which Cary Grant and Deborah Kerr fall in love aboard an ocean liner, fail to connect at an Empire State Building rendezvous, and are reunited only at the very last minute during a thoroughly shameless and well-nigh irresistible finale.

“All the women I know love An Affair to Remember,” Ephron said. “But nine of every 10 men throw up during that movie.”

You may recall that the lead female character in Sleepless in Seattle — Annie Reed, a determinedly practical but hopelessly romantic newspaper writer played to perfection by Meg Ryan — is addicted to An Affair to Remember. And that this addiction is a major reason why, even though she's engaged to a reasonably charming fellow (Bill Pullman) who might make any woman reasonably happy, she can't help thinking there must be more to romance than reasonableness.

Annie, who lives in Baltimore, finds herself unreasonably interested when she hears a caller from Seattle late one night on a talk-radio show. Sam Baldwin (Tom Hanks, giving one of his most under-rated and emotionally complex performances) is wallowing in memories of his late, much-loved wife. He knows he must get on with his life, if only to be the kind of father his precocious son (Ross Malinger) needs and wants, but he suspects he'll never find anyone else to make him as happy as he used to be.

All of which leads to something best described as love at first listen: As Sleepless in Seattle progresses, Annie begins to wonder if, much like Gary Grant and Deborah Kerr, she and Sam are made for each other.

“This is a movie,” Ephron said, ''about six weeks where one person decides she's going to meet this other person, because she's decided this is destiny knocking on her brain.”

Ephron laughed at my suggestion that Annie's ideas about romance — indeed, everybody's ideas about romance — have been unduly influenced by old movies.

“Actually,'' she said, ''I would say movies have warped our ideas about romance. I think that's one of the most delicious things about making a movie like Sleepless in Seattle — you get to do all the stuff that movies do to you. I kept saying this to everybody: ‘This is not a movie about love, it's a movie about love in the movies.’”

Throughout the 12 weeks of filming, “We kept talking about all the ways that your brain is just completely fried by seeing movies. You get the most unrealistic expectations, so that, if you meet someone, and there isn't this kind of divine, inhuman banter, you think perhaps this is not love.

“And I will tell you — about 11 years ago, I had a date with someone that I absolutely hated. And it truly crossed my mind that maybe we were meant for each other. Because I'd seen so many movies in which people who just despised one another fell madly in love.”

(Presumably, this Date from Hell was not author-screenwriter Nicholas Pileggi, whom Ephron married in 1987.)

At one point during Sleepless in Seattle, Sam insists the only movie that ever made him cry is — no kidding! — The Dirty Dozen. When a female friend (played by Rita Wilson, Hanks' real-life wife) tries to explain the appeal of An Affair to Remember, Sam reacts pretty much like a 5-year-old who’s just been ordered to eat his broccoli.

Ephron, of course, had a much higher regard for the sentimental impact of old-fashioned romantic movies.

“What we kept hoping,” Ephron said, “was that we would make a movie about those old movies, and then become one. What I kept saying over and over again to everyone as we were making it was, ‘Reality always gives way to beauty.’ I always wanted to make the choice for the beautiful prop as opposed to the realistic one.

“Like, the Empire State Building observation deck looks twice as good in our movie as it does in real life.”

Almost as good, in fact, as it looks in An Affair to Remember.