Tonight I reached out to kill something -- and stopped. I actually had to take a second look at it to realize why I'd stopped. It's a lacewing, which is a beneficial insect.
Apparently, the "Identify Friend-Foe" feature in my head is sufficiently permed to block a kill command even when I wasn't consciously paying attention. I had two automatic routines running in the background while working on a poem, one activated, and the other canceled it.
And people wonder why my wetware is such an energy hog.