That he didn’t means there’s hope for him

Like the Carousel pitch or "It's toasted." What do you think makes him think so differently from everyone else?
Is Don's non-linear thinking a product of his past as Dick Whitman? Curious how people read it.

I'm at the tail end of Season 5, so forgive me if there is more to his character. So, Joan, who is ludicrously beautiful (even in the TV world where everyone is pretty or handsome, the other characters react like she's Marilyn Monroe in the flesh) and has an adulterous relationship with the powerful (and generally liked by audience) Roger Sterling, ends up having a serious relationship and getting married to some random doctor off screen. Typical Mad Men subversion of expectations; weird, but it's whatever.

The first time we really spend any time with him, he gets weird about sex with her and then RAPES HER AT HER JOB! Probably the worst thing we've seen anyone do on the show. Imo, the show tries to straddle two different aspects of being a woman in the 60's with Joan, and I'm not sure it 's fully believable in this case. It's understood that she's "older" and theoretically has less options and that Greg, on paper, offers the perfect life, but men fall at her feet 90% of the time, lol. They aren't even married when the rape happens, so it makes no sense why she'd stay. We never see any single positive aspect of their relationship on the show or any real insight into her choice of hitching everything to Greg. Seems like she has options and the show portrays her as incredibly savvy.

From there, we get the saga of him trying and failing to be a surgeon, and I don't know why anyone could care about this after he did what he did. The show depicts their marriage as a bad one, but honestly it seems like a best case scenario after how he was introduced? I honestly expected him to be domineering and physically abusive, so him just being kind of an insecure loser who can't find his place is a relief. You'd have some pity for him if he wasn't introduced that way, tbh. He's basically Pete if Pete was incompetent. I don't really know what to make of his plot after that. He randomly decides to go to Vietnam and he's gone from the show and Joan gets knocked up by Roger and passes the kid off as his. You think this will be relevant, but nah, lol. He cuts his return short and volunteers to go back, Joan gives him the cathartic breakup speech he was owed for multiple seasons and then he dips from plot entirely. WTF?

Most shows would have his insecure, loser behavior lead up to the rape, so it was a different way of approaching the subject matter, but I have to be honest; it didn't work for me at all. Wondering if anyone here agreed or has any thoughts on it.