Anyone notice that Don's reluctance to go to the dentist may have been due to dental records? I don't know if those were in place at the time just curious.
I too agree that Pete is a very complex character. His speech to his fling was really well done and I think he should be considered for an Emmy for best supporting actor. His work has been very well done this season. In particular, I like that Pete is seemingly halfway between worlds constantly. He is not young but not old, he is well off but not uber wealthy. He is decent looking but not handsome. He always wants someone, or something, to validate this image he has of himself in his mind. He has little empathy for others (i.e. Joan, Roger, his wife etc.) because he has little of it for himself. I wonder if he was more upset by the fact that she could not remember who he was, or if he lost the affection and lust of a woman he felt he could never get but ultimately "seduced" (given her histrionic nature, it is likely his charm or looks had little to do with her decision to make love to him).
In stark contrast, we have Don, who has an identity so diffuse and hollow that it can hardly stand any cracks. Even when he attempts to tell the truth or show genuine concern (i.e. telling Sally about Anna, going to Lane's wife, his speeches to Lane/Joan) it is clearly always about him and his need to either show everyone how to act (i.e. move on with life) or to reinforce his identity as "the man" (i.e. telling Joan the Jaguar scandal wasn't worth it, clearly it was to him, but not on those terms). I don't deny that he has empathy, clearly he does, but he often needs to fill the void within himself with "something" and that void is clearly sexual conquest, financial conquest, or having power and control over others. We see how vulnerable Don is many times in the series. Any chance that his world will come apart and he either has the instinct to run, rant and rave, panic, or show reluctant cruelty (someone labeled it tough love earlier). The montage at the end of this episode shows how the various characters handle themselves, Peggy trying hard to feel proud and satisfied, Pete drowning out the outside world with headphones focusing intently on himself, and Roger, bearing himself to the world high on LSD, unable to face reality for what it truly is.
I think we feel underwhelmed because we feel the hallowness of these characters. Not in terms of complexity, but in terms of their sense of self, identity, and internal fortitude. Lane's suicide was the true finale, that the only alternative to the nausea (in Sarte's use of the term as the impending doom of nonexistence and the loneliness of the human experience) these characters experience is death. Without taking that step, they are doomed to repeat the same patterns over and over, banging their heads against the wall to find fulfillment.
That being said, this show really does need to focus on the racial issues in society next season or it teters dangerously close to being a blueblood dramedy...