We start with a long shot of Don diving into a laned pool as he voices over that it's said that as soon as you have to cut down on your drinking, you have a drinking problem, and I'm glad that he's finally becoming aware of his alcohol abuse, even if it sounds like the "they" in this case is Bazooka Joe. Cut to Don writing these DVOs down in a journal as he goes on that his mind is a jumble and he can't organize his thoughts, "and typing feels like work." And I'm guessing with Miss Blankenship as his secretary, he's having to do a lot more of it to cut down on random spelling errors and his correspondence ending up in Timbuktu. By the way, even though Don is home and this is apparently a day off work, he's dressed and groomed and not entertaining women whose names he forgot/never knew/is not interested in because they're prostitutes, so between this and the journal, it seems like last week's interaction with Peggy plus the closure of Anna's death may have inspired him at least to try to pull himself out of his downward spiral. Also, while we're here, it's definitely a departure for this show to employ voice-over so heavily when (a) I don't remember it ever having used it and (b) it by definition somewhat sacrifices the subtext and ambiguity that the show revels in. However, I think it makes sense for this episode given that, thanks to both the increasing prevalence of people talking about their feelings this season and him being at a real crossroads, he's engaging in self-examination for the first time in his life; we really do need to know what he's thinking in order to advance the story they're trying to tell here.
Anyway, Don sips some coffee as he confesses he's never written more than two hundred and fifty words at a time, not even in high school, and if he actually existed I'd love to show him a recap so he could blanch at the length and then laugh at me. He pronounces his old self lazy and then expresses his regret that he never graduated, as "everything could have been different." If he's saying that he then could have gone on to college, I hate to disappoint him, but he wouldn't even have made it past the application process writing only two hundred and fifty words. Either that, or I did it waaaaaaay wrong.
Cut back to the pool, where Don finishes up a lap and then coughs in such a smokerly way that the lifeguard asks him if he's okay, and Don waves him away all "Just let me hack some yellow stuff up into your pool and then I'll do another couple laps." Not that he's the only one, I'm sure.