It does feel odd to talk about all this, but because my entire body and mind felt more alert, it's like I was often able to sense possible negative or stupid outcomes via some bodily reactions (e.g. feeling strange in my stomach just before I was starting to get upset etc). No idea how much of all this should be dubbed placebo or wishful thinking, but at the moment, I haven't had a consistent meditation practice for several years, and I am definitely doing much worse mentally. Thoughts seem to be much more scattered, mental consistency is definitely lacking as compared to those previous times.
It is very much possible, though, that the current state of the world and, in the case of the region in Europe where I live, the war in Ukraine, have a considerable negative impact on the mental well-being of our entire population. Not to mention long-term mental effects of the covid lockdown. There's probably quite a bit more "brain fog" in the whole society these days, as compared to e.g. the previous decade. I have also gotten older, which probably matters somewhat. On a personal level, though, I still remember how much easier it was to handle stress of many kinds when I was actively meditating.
As a side note, meditation is definitely not about "feeling great" -- there's even a term called Dark Night to describe the struggles a serious mediator will probably face. But I did feel more honest and it was a lot easier to maintain focus on long-term goals (particularly those related to compassion and cooperation with others) during the daily meditation practice.
Another relevant thing is that it's not a good idea to expect quick results. I think meditation "works" precisely because the deeper effects (change in one's ethical character?) show themselves slowly, over time. When I was in a Vipassana retreat several years ago, I remember the teacher (a very inspiring elderly lady from Germany) said something like "often times, I just sit". Not expecting instant results is probably also a skill that one learns over time.