Lisa Kudrow knew that they didn't know what she knew about Conan O'Brien. 

The Friends alum recently opened up about supporting the Conan O'Brien Needs A Friend podcast host ahead of his Late Night hosting debut in 1993. 

"I just knew, ‘You're trying to replace David Letterman. No one replaces David Letterman,'" the 60-year-old said she told her longtime friend in a Vanity Fair interview published on Dec. 20. "‘You're no one.' It can't be anybody that an audience would know."

The Comeback actress was convinced that Conan—who also described his television debut audition as "linguine meeting marinara sauce for the first time"—was perfect for the Late Night position because he was unrecognizable to the general public. Not to mention the former Saturday Night Live writer's comedic wit. 

The idea came to Lisa as Conan—whom she dated briefly before they became famous—described who he was searching for in David's replacement.

The 60-year-old—who was involved in the search for the Late Night hosting spot—was looking for someone who could interview celebrities, but also "knew enough and who read enough to ask intelligent questions" of lesser-known guests like authors or scientists.

"And I said, ‘So it sounds like you want you,'" she continued. "And he said, ‘That would never happen.'"

Conan was obviously wrong, going on to host Late Night for 16 years before transitioning into The Tonight Show. His tenure on the latter show was brief, with him vacating the desk in 2010 after one year over a dispute regarding his and Jay Leno's timeslots. He later moved to TBS where he hosted Conan for 11 years. 

"Try and do what you love with people you love," the host said in his very last Conan episode when the show wrapped in 2021. "And if you can manage that, it's the definition of heaven on Earth. I swear to God, it really is. So good night. Thank you very much."

And the late night host's career trajectory may never have even happened if not for his ex girlfriend Lisa. Curious about more celebs you didn't know who dated? Read on.

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The Yellowstone actor and Sweet Valley High alum have been married since 2006 and have three children together, sons Ryland and Colt and daughter Steely Rose. 

They played doomed lovers twice, in 1990's Too Young to Die? and 1993's Kalifornia, but in real life they had a perfectly lovely relationship.

"I still love the woman," Pitt, who was Lewis' date to the 1992 Oscars when she scored a Supporting Actress nomination for Cape Fear, told Vanity Fair in February 1995. "There's some real genius there. I had a great time with her...It was one of the greatest relationships I've ever been in. The problem is, we grow up with this vision that love conquers all, and that's just not so, is it?"

It wasn't just a Gen X fever dream, they really closed out the 20th century as a couple after, legend has it, being introduced by Gwyneth Paltrow (who famously dated Damon's best bud Ben Affleck). They split up in 2000.

After the fact, Damon called Ryder a "great woman" in a 2004 Playboy interview, while Ryder told Black Book in 2009, "Matt couldn't be a greater, nicer guy. I'm really lucky that I'm on good terms with him."

There was something about their chemistry at the 2003 Nickelodeon Kids' Choice Awards, where Diaz presented Timberlake with the award for Best Burp—because they dated for almost four years, seriously enough to issue a statement when their relationship ended in 2007, "mutually and as friends, with continued love and respect for one another."

The Scandal star appeared on the cover of InStyle Weddings in 2005 when she was engaged to the Big actor, but they split up in 2007.

Madonna never addressed the story that she dated the rapper, who was killed in 1996 when he was only 25, until 2015. When Howard Stern brought up her infamously feisty 1994 chat with David Letterman, she explained, "I was dating Tupac at the time, and the thing is...he got me all riled up on life in general."

After her divorce from Ryan Phillippe and before marrying agent Jim Toth, Reese starred with Jake in the 2007 thriller Rendition and they dated for a couple of years.

"She is, as I would say about most of the women who I'm close friends with or had relationships in my life," Jake said admiringly of his ex, "one of the smartest, strongest people I've ever met."

Before marrying Livia Giuggioli in 1997 (they separated in 2019), Firth had a five-year relationship with Tilly that produced son William Joseph Firth, who was born Sept. 20, 1990. The younger Firth is also an actor who appeared with his father in Bridget Jones's Baby.

This was them: The U.S. Open champ courted the A Walk to Remember star between 2003 and 2004, but ultimately it wasn't a love match.

"He broke my heart," Moore told Howard Stern in 2018. "I was a kid, he was a kid. I started dating him when I was 18."

You oughta know by now that one of the most enduring mysteries in music history is who inspired Morissette's iconic 1995 single—and the Full House star is at the top of the list of maybes! Morissette denied it in the 2021 documentary Jagged, but that's a tough pill to swallow.

"Oh yeah, I love her music," Reynolds told People of his then-fiancée in 2005. "It can be awkward when she walks in and I'm listening to it in my underwear dancing."

Two Canadians, a ring and a trip to the altar that never happened, but their 2007 breakup after four years together was very polite.

You can't blame the Mad Men star for liking funny guys. Jones and Sudeikis dated for a few months in 2010, five years before she briefly dated Will Forte.

The Good Will Hunting stars paired off in real life, too, but they didn't drive off into the sunset together.

"Well, I'm single," Damon said on The Oprah Winfrey Show in January 1998. "I was with Minnie for a while, but we're not really romantically involved anymore. We're just really good friends, and I love her dearly….I care about her a lot. We care about each other a lot. It wasn't meant to be, you know? And if it's not meant to be, then it's not meant to be."

The pronouncement was a bit too public for Driver's taste. "It's unfortunate that Matt went on Oprah," she told the LA Times later that year. "It seemed like a good forum for him to announce to the world that we were no longer together, which I found fantastically inappropriate."

The stars met on the set of the 1981 movie Excalibur and eventually lived together (Neeson says Mirren gave him his first driving lessons) before they broke up in the mid-'80s.

"I should be so lucky and be honored to have spent three or four years with that lady," Neeson told ET Canada in February 2023. "She's really something else."

Finding love in Jurassic Park? Talk about a meat cute.

The co-stars began dating after filming the 1993 blockbuster, with Goldblum telling The Chicago Tribune at the time, "I was struck, I'd been a big fan of hers. I think she's an amazing actress, and a spectacular person. I was struck from the beginning. But after the movie we realized we liked each other."

They got engaged in 1995 but ultimately split two years later. They reunited on-screen for the first time in 2022's Jurassic World: Dominion, the sixth installment in the franchise.

The X-Files alum was in a relationship with The Crown creator between 2016 and 2020. Anderson won an Emmy for her turn as Margaret Thatcher in the Netflix hit in 2020.

According to Arquette, the two dated while filming their 1995 Western Wild Bill.

The Clueless actor confirmed a little-known rumor during a Reddit AMA chat in November 2015, revealing that he used to date the actress. The two had starred in the 1992 TV movie Desperate Choices: To Save My Child.

"She was my first actress girlfriend," he said. "We had a long distance relationship for a long time. I was so into her."

E! News exclusively broke the news that the Real Housewives of New York star and Modern Family actor were a pair in 2015. But by the following year, they had split. 

The Southland alum and the actor, who played Theo Huxtable on The Cosby Show, dated for several years before calling it quits in 2013.

The famous bachelor was actually settled in with Preston pre-John Travolta back in 1987. They even lived together and had a potbellied pig together before breaking up in 1989.

The Top Gun star and the legendary diva dated back in the '80s. She was 14 years his senior.

Before he was Heidi Klum's ex, he romanced a different supermodel, who was 11 years his junior.

The duo reportedly started dating after meeting on the set of the 2005 film Brick, but they only stayed together for six months.

The Dawson's Creek alum and the Josie and the Pussycats star dated for about a year back in 2002.

The NCIS: LA stud and America's sweetheart dated way back in 1993, when 17-year-old Witherspoon first moved to Los Angeles.

The man who now rocks the Iron Man suit for Marvel admitted that drugs and alcohol were to blame for the end of his seven-year relationship (1984 – 1991) with the Sex and the City star. "I liked to drink, and I had a drug problem, and that didn't jibe with Sarah Jessica," he admitted in an a 2008 interview with Parade, "because it is the furthest thing from what she is. She tried to help me. She was so miffed when I didn't get my act together."

The Friends alum and The Hangover star supposedly had a fling 2003, but it didn't last long enough to be more than a little blip on the Hollywood hookup radar.

The 2 Broke Girls actress dated her Thor costar briefly in 2010, appearing very cozy while attending Comic-Con to promote the Marvel film. But their relationship fizzled by the time the movie premiered the following year.

In 1999, way before he wed Blake Lively, Reynolds dated the 3rd Rock From the Sun star. The duo even attended the premiere of The Green Mile together.