1. Hendricks was so nervous on her first day of shooting, her hand shook while she tried to light a cigarette in her first scene.
"I remember being so scared about this scene," she said. "I bet if you look very, very closely, my hand was shaking. I was so nervous lighting that cigarette ... And these old-fashioned lighters do not always light."
2. And Joan's signature walk originated because of Hendricks' struggle to move in her constricting dress.
3. Weiner wanted to avoid mimicking Aaron Sorkin's signature "walk and talk" in the pilot.
4. Everyone makes fun of the way Aaron Staton (Ken Cosgrove) smokes.
5. Roger was almost killed off in Season 1.
6. It wasn’t Weiner’s idea to cast his son Marten as the Drapers' neighbor, Glen Bishop. In fact, he was very wary.
7. And he did not get special treatment.
8. He also refused to get close to January Jones during one of their first scenes.
9. Slattery and Jones had fun filming the moment when Roger hits on Betty.
10. Weiner intentionally told Slattery about Roger's blackface episode at a party.
11. And some of the writers didn't want to be associated with it.
12. Slattery thought it could end his career.
13. And he had an uncomfortable encounter with a police officer while in full blackface.
14. "The Suitcase" was an episode that was meant to save money.
"This was our saving-money episode. It's what they call in television 'the bottle show.' A bottle show is a show that ... limits the elements of the show — there's one location with as few people as possible," Weiner said, joking that bottle episodes actually end up being "the most expensive episodes that you ever do." "You really want it to work that way ... but this was a special script — a script that was not planned in the beginning the season," he said. "It's what we call a filler ... it was like an extra episode that didn't really advance the story except that it told the entire relationship of these two people."
15. And the bar scene between Peggy and Don in "The Suitcase" came from the writers' list of questions they'd never answered.
"We made a list in the writers' room before we did this ... of everything that had not been talked about, because so much of the show depends on people not talking to each other," Weiner explained. One of those questions was: "Doesn't Peggy wonder why Don has never hit on her?" "And this is Season 4, where he seems to be the least picky he's ever been. These are not my words, by the way," Weiner added.
16. Speaking of bars, Hamm thought it was important that Don’s alcoholism eventually be depicted as no laughing matter.
17. But Weiner worried showing Don’s drinking as a problem would turn viewers off.
18. Peggy and Roger's legendary Season 5 scene in "Mystery Date” was Weiner's response to his own notorious back-and-forth with AMC and Lionsgate.
Weiner first started negotiating with AMC in 2010, after the show's fourth season, and they didn't reach a new agreement until March 2011, sidelining Mad Men for a year and a half — the Season 4 finale aired in October 2010 and Season 5 didn't launch until March 2012. "I was a little bit fascinated with negotiating at that point and the different aspects of it," he said with a smile of this Peggy-Roger moment. "It's really the only place it kind of showed up on the show."
19. There was a sign that Lane would be leaving the show.
Lane (Jared Harris) wound up committing suicide at the end of Season 5, but before Harris was even made aware of his character's fate, he not only had a feeling, but he also sent a signal. “If you rewatch the episode where he embezzles the money with the check, he takes the check, he writes Don Draper’s name on the check, he picks it up, and he waves goodbye," Weiner said. "He knew. I had not told him yet, but he knew."