'How I Met Your Mother' Boss on 9 Seasons: 'We Got Away With It!'

Saturday's "How I Met Your Mother" PaleyFest panel — featuring Josh Radnor (Ted Mosby), Cristin Milioti (the Mother), Cobie Smulders (Robin Scherbatsky), Alyson Hannigan (Lily Aldrin), and executive producers Pamela Fryman, Carter Bays, and Craig Thomas — was a celebration tinged with sadness. With only three episodes left to air in the series, the cast is already parting ways.

Neil Patrick Harris did his best, though. He's currently rehearsing for "Hedwig and the Angry Inch," which opens on Broadway in less than two weeks, but he joined via Skype — and managed to spend much of that time shirtless. He was leaving to do a secret warm-up show for "Hedwig" and tried to end his Skype call by stripping off his shirt and shouting, "I gotta go be a rock star, everybody! Take it easy!" He then realized that he had forgotten to thank Fryman, who he called the "ultimate mother of the show," so returned for another minute to heap praise on her.

1. Harris loved being able to play the enormous arc of Barney's character, so the entire final season was great for him. But, asked to pick a single favorite moment, he said, "I guess getting to say my vows to Robin Scherbatsky was a highlight."

2. Harris had kind and beautiful words for everyone in the cast and crew: He called Hannigan "the heart of the show" and Radnor "the soul of the show." And as for Smulders? "There is no one in my life that I would rath— there is no girl in my life that I would rather..." drew a huge round of laughs and applause from the crowd.

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3. Milioti on the final scene: "The last scene that I filmed was the scene that I tested with," which made it hard to get through without crying. But, "It was amazing to have it come that full circle."

4. Fun fact: The title on the sides for that audition scene: a USC student film called "Magnolias at Midnight." "If somebody found this script on a bus," said Bays, "We tried to find the title that no one would want to read."

The "HIMYM" cast reveals what they stole from the set:

5. The show is very autobiographical. Thomas and Bays, like Marshall (Jason Segel) and Ted, went to college together. Thomas and his wife, like Marshall and Lily, have been together since their freshman year. And Thomas said, "We moved to L.A. and desperately missed New York and that was the nostalgia in the show; that was the narrator looking back on his time. We were 29 and looking back on our days of youth in New York and that's what inspired it."

6. Also, according to Thomas, his wife cast Lily, who is the fictionalized version of her. "'Alyson has to play me if you're doing this show'," he recalled her saying.

7. Again and again, the friendly and loving environment of the set was mentioned. It was due, in large part, to Fryman, who directed almost every episode of the series. "I was surrounded by loveliness," she said citing the selfish reason, "If you're going to be somewhere for 12 hours a day, you'd better make it a pretty nice place. So with the help of everyone on this stage, we made it just that. It was the greatest environment in the world."

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Everybody was asked for their "Pinch Me Moment" — the moment they realized that the show was something special.

8. For Bays, it was the two-minute date from season 3's "Ten Sessions," an ambitious undertaking that required the utmost precision from the cast and crew. "It was a crystallized moment of how much fun it is to do this job and how much fun it was to work with these people."

9. For Thomas, it was the yellow umbrella moment on the train platform, which is the very last thing they shot for the series. Not only because it was beautiful and perfect, but also because of "this mischievous and slightly gleeful feeling of, 'We got to wait nine f---ing years before we met the mother! We got away with it!'"

10. For Fryman, "The episode is 'Drumroll Please' [from Season 1]. It's at the very beginning. It's that wonderful set with the grand piano. It's sitting onstage with Carter Bays and watching this magic and thinking — this is the most fun I've ever had in my life."

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11. For Hannigan, it was during the shooting of the pilot. "I walked outside and there were hundreds of butterflies." She watched them with some of the cast and crew and, "It was the strangest. It was so beautiful. And I thought, 'Well, if that's not a sign, then I don't know what is.'"

12. For Smulders, it was filming "Let's Go to the Mall." It was more than the fun of "playing a character who's playing a character" and it was more than convincing the producers that she could sing — "I do OK in the shower and in the car on the way to work." The episodes that involve music videos requires an extra day of shooting and all the departments to step up to make it happen, but getting to "create something that's totally different — it's just a blast!"

13. For Radnor, shooting a scene on New York Street for "Come On." "There were these big lights flooding onto the set and this huge rain machine — very cold rain — and I was getting drenched and screaming up to the window. And it was like a Stanley Kowalski [the "Stella!" line that helped make Marlon Brando famous] moment. And I felt like, I'm from Ohio and I really feel like I made it in show business."

14. For Milioti, the song "La Vie en Rose" is an important song for her family and getting to surprise them with her ukelele rendition of it in the 200th episode was an unexpected and poignant coming together of her family and work. "It was a very 'How I Met Your Mother' moment!"

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15. Fun fact: Bays plays "La Vie en Rose" to his children on a ukelele purchased during his wedding trip to Hawaii, which is where the idea to use the song in the show came from in the first place.

16. Thomas is thankful that the chemistry between Milioti and Radnor worked. "We were waiting so many years for Cristin Milioti to show up," remembering the pressure they were under, after an eight-year build, to get the character right. "Imagine if we cast that role wrong? There'd be no show! We'd just have to issue an apology and go off the air."

17. Three of the casts favorite running gags: For Hannigan, "Thank you, Linus. Especially the one in the doorway." Radnor loves both the interventions ("They clearly got a professional banner made...") and telepathic talking (Hannigan said, "We mainly like that one because we don't have to memorize!").

18. Milioti dropped out of theater school. "You want to go to theater school? Roll around in a dark room for a little bit. Pretend to be a zebra and pay someone $80,000."

19. Hannigan's advice to young actors: "Don't take the criticism to heart. I was told I wasn't funny enough to be on television when I was a kid."

20. Thomas on whether there will be any more musical numbers: "We won't confirm or deny, but no."

Watch a preview from the March 17 episode:

"How I Met Your Mother" airs Mondays at 8 p.m. on CBS.