Almost a full year later, I think that I finally remembered the third thing from my followup post on accidental life outcome patterns. I'm not completely certain that this was the third thing I had in mind at the time, but definitely adds to a general perception of things going downhill all at once.
Specifically, my longtime barber had an accident sometime in the summer of 2016. This barber, Bud, had been cutting my hair since before I could process speech—since I could grow actual hair, in fact. He was at least in his 80s around the time of his motorcycle accident, and what his family described on the answering machine would be serious at any age. I'm still not sure if he recovered but he definitely couldn't continue cutting hair.
This is notable for me because a) yet another reminder of human frailty and b) I never asked Bud what the normal haircut he gave me was called. I haven't been truly satisfied with another barber since then. I don't really think "short" is a complicated request, yet I keep coming out of the barber shop looking the way I used to go into it. If I had a bit more time to burn, I would just go to different shops on a rotation until I tricked them into getting it short enough, but I don't, so I haven't.
Compared to the other things, this consequence for me personally is kind of trivial, so I'm not massively surprised that I forgot it. Also, it falls into a slightly different category: not something which had finally started going well, but an erstwhile constant that suddenly disappeared. Even so, it adds to a generalized perception that things suddenly fell apart in the late summer and autumn of 2016.
In reality, however, the conditions were all set for failure modes to occur; I just hadn't noticed and/or acknowledged them yet. Picking up on problematic trends before they become serious problems is a useful life skill, so I guess this combined ordeal will be a valuable experience in the end. Nevertheless, I can't shake the feeling that many—if not most—personal and family problems confronting the socio-economically well-off are artificial and could be avoided with a much smaller amount of foresight than we need in practice.
Oh well. Everyone has to start somewhere.