Hawaii is such an important part of 50 First Dates that it's impossible to picture the movie being set elsewhere. But Segal says that in the original script, "the story took place in Seattle." It was Sandler's idea to move it to Hawaii, as the actor reportedly thought that the location would bring more opportunities to the story and be a beautiful backdrop for Henry and Lucy's romance.

The ending to 50 First Dates is meant to show how Henry continues his romance with Lucy despite the odds, with him waking her up every morning with a videotape that explains their love story, including their wedding and the birth of their daughter. But originally, the ending was far different, according to the director. "They woke up in bed together and she had painted a mural — or he had painted a mural for her, to remind her — kind of like the videotape," explains Segal.

The movie's soundtrack is nearly as memorable as its plot, featuring classic '80s songs like "Slave To Love" and "Every Breath You Take" re-imagined with an island vibe. And, it turns out, Sandler is the one to credit for it. "Adam had the idea of doing '80s covers with an island vibe," recalls Segal.

The filmmakers were able to get a large number of popular artists to participate. "We started getting all these great bands come in to do covers — we had Seal do a cover ("Lips Like Sugar"), and then 311 did a cover ("Lovesong')," says Segal.

And the soundtrack still holds up today. Adds the director, "I actually hear our 50 First Dates versions of the '80s songs more than I do of the '80s songs these days."

50 First Dates features several well-known comedians in small roles, including the Happy Madison guys (Allan Covert and Kevin James) and Maya Rudolph. But, according to Mussenden, the star that everyone freaked out over was another SNL alum, Dan Aykroyd.

"I'll tell you who was the superstar when he walked in the room that even Adam bent a knee: Dan Aykroyd," recalls Mussenden. "[He] came in and couldn't be a sweeter guy, he was just a lovely, lovely man, and everybody just [was like], 'Oh my god, there's Dan Aykroyd!' From Schneider, to Covert, to Blake [Clark], to Maya."

Much like in his previous Barrymore collaboration The Wedding Singer, Sandler wrote his own song for this movie. "Forgetful Lucy" has the comedian's signature humor with a romantic twist, with lyrics discussing why Henry loves Lucy despite her amnesia.

"He wrote that song 'Forgetful Lucy,' and it's very sweet," says Segal. "It's funny, but I think they're at a stage in that story where you're really falling in love with those characters in that relationship."

Ula, Henry's wild best friend, is easily one of Rob Schneider's most outlandish characters, and interestingly, he was based on a real person Sandler knew. The duo met while the actor was "on a trip to Hawaii," says Segal, and the real Ula, like the character, had "lost an eye and had a bunch of scars from, I guess it was a shark encounter."

Though many consider 50 First Dates to be a beloved rom-com, the film has received plenty of criticism for its portrayal of Alexa (Lusia Strus) an androgynous character who is repeatedly the subject of cruel jokes about her gender. Segal explains that he didn't initially see why the jokes were problematic.

"We got some comments that there was a lot of gay humor in the movie, and I said, 'Gay humor?' I didn't understand what they meant," the director says. "But I think some people actually might of bought that she was a man, because [characters] said she was a man, and she kind of looked masculine in her wardrobe and how we did her hair. And that wasn't intended — she was a woman —but I think it got confusing."

Segal does acknowledge now that a 2019 audience would likely be receptive to those jokes than viewers at the time. "Because they were done in the early 2000s, we got away with them a little easier, but I'm not 100 percent sure that some of those same jokes would play today," he says.

Before 50 First Dates, Astin had spent years filming the Lord of the Rings movies back-to-back. But after wrapping up the series, he decided to tackle extremely different roles, appearing in the dark comedy Elvis Has Left the Building the same year as 50 First Dates. And despite not having much experience in the rom-com genre, he left an impression on the latter film's casting director.

"Sean Astin was the last guy in the door to play that role. He sent me a tape from Seattle, and I asked the guy to wait until we saw the tape because I had a good feeling about Sean, and he was terrific!," recalls Mussenden.

Henry's way of creating a romantic spark with Lucy every day even when she doesn't remember him might be questionable to some, but according to Segal, the story is actually beneficial to some couples in relationship counseling.

"A couple of psychologists that I've bumped into over the years say that they use 50 First Dates as a tool in counseling couples to show how much you would do for your spouse or your significant other," says the director, adding that these therapists view Henry's actions as "pretty admirable, and something you should try in your own relationships — to do whatever you can."

Fifteen years after 50 First Dates' release, many fans still have mixed feelings over the film. Some think it's one of the best rom-coms of all time; others think the story is straight-up creepy. But regardless, the movie has clearly held up as one of the most memorable rom-coms of the early 2000s, for better or for worse.