So I tried the trick where you smile at things to trick your body into thinking you're happy. First off, it was surprisingly hard to put a reasonable smile on my face. Just pushing the corners of my mouth up seemed like cheating, because I knew it wasn't to my eyes yet, and it was serious work to crinkle up the corners of my eyes in proper smile-eyes. And as I walked along, I kept thinking that surely the fence, and the bush, and those things I was smiling at wouldn't be fooled by this fake smile, would they? But I supposed they would be, because it was a pretty good fake smile. And I didn't really want the bush to think I was mad at it. Which suggested (since I was now worrying about the bush's feelings) that I wasn't as angry as I had been moments before. Which, as it turned out, was true.
I find it very convenient that this sort of trick works so well, but it's also somewhat creepy. Like when I touch a hot thing, and my hand jerks back and my mouth says "ouch", and only then does my poor brain look up from what it was doing to say "wait, did something just happen?" I don't mind that my heart beats without me having to micromanage it, but it's astonishing how much gets done in the realm I think of as "me" without me really driving it (or, in this case, driving from the passenger side).