Further meditating on the problem of progress, I noticed a few other things which had been going right in the world and my personal life that contributed to the perception that things were moving a specified direction.
One of the most memorable things happened on the winter solstice of 2015: SpaceX, after many failures, successfully landed a rocket on the ground. It's worth noting that this technical triumph was underscored by multiple sorts of suffering in my surroundings. I'd literally fallen and hurt myself pretty badly that evening, and then been dragged to a very uninteresting Longest Night church service that ended mere moments before the landing. My attention was entirely directed elsewhere than the mundanity around me.
At this point, landing rockets has become essentially routine. I don't even watch launches anymore, though part of that is because I don't know when they're happening without Twitter. Maybe there's an email alert service for that.
Another thing which improved in the first half of 2016 began a week after the SpaceX landing. After an entire semester apart, I drove up to St. Paul to enter the new year with my then-girlfriend. It'd taken a long time to finally get together, and then we hadn't arranged to meet up again for the entire fall. But after that, we saw each other at least every three months until breaking up. This felt like emotional progress, getting to spend time with someone I loved on a regular if infrequent basis.
...there was going to be at least one other thing, but it's not coming back to me now. Hopefully this gets the point across: largely by accident, a lot of factors were lining up in what seemed like an organized pattern, only to diverge at a later date. Homo sapiens' overactive pattern-matching instincts strike again.
Try not to make that mistake in your own future. When things feel like they're going well, don't assume that they'll stay that way. Stuff can always go wrong, and—all other things being equal—probably will.