In the later seasons of MAD MEN, Don gets a hot secretary, Megan, and then up and promptly marries her. Whether this is a good or poor idea is left up to the reader, but Megan wants to be an actress, like so many hot chicks who crave attention, and Don sets her up to be a copywriter, then an actress, and, because this is TV, she succeeds: Don Draper magic works. Megan’s “career” suddenly becomes important. She and Don plan on moving to LA for her acting career. Don later decides he can’t go, but that Megan should go anyway. She becomes a glamorous LA woman. When Don arrives in LA, he doesn’t fit in with her life any more; she’s outgrown him, or grown in a direction orthogonal to him. In one of their last real interactions, she sets up a threesome for him, but it’s a melancholy, goodbye threesome, not a fun, life-affirming threesome. “Enjoy it,” Megan seems to be saying, “because we’re done, and this is a parting gift.”
Don thinks he’s going to show up in LA and Megan is going to be his, like she was in NYC… but she’s not his, not anymore. She’s not the girl, the secretary, he first met. You can’t turn a famous actress back into a secretary just hitting the big city for the first time, not when you have made her into something impossible to achieve for most women. In programming we call those “one-way functions:” easy to compute but difficult or impossible to reverse (without them, all you crypto HODLers would be hosed). Turning a secretary into a famous actress is a one-way function: she’ll never be the same, even though Don would like her to be. He can’t swoop in and have “her” again. He’ll never be the same in her eyes, because she’s changed… and been exposed to numerous high-status men. Don can have sex with her, but she’s become an actress, and the sex is sex, not her life. Sophistication goes up, rarely down.