Sometimes, it’s the little tech annoyances that sting the most
Anyone who has suffered the indignity of a splinter, a blister, or a paper cut knows that small things can sometimes be hugely annoying. You aren't going to die from any of these conditions, but it's still hard to focus when, say, the back of your right foot is rubbing a new blister against the inside of your not-quite-broken-in-yet hiking boots.
I found myself in the computing version of this situation yesterday, when I was trying to work on a new Mac Mini and was brought up short by the fact that my third mouse button (that is, clicking on the scroll wheel) did nothing. This was odd, because I have for many years assigned this button to "Mission Control" on macOS-a feature that tiles every open window on your machine, making it quick and easy to switch apps. When I got the new Mini, I immediately added this to my settings. Boom!
And yet there I was, a couple hours later, clicking the middle mouse button by reflex and getting no result. This seemed quite odd-had I only imagined that I made the settings change? I made the alteration again in System Settings and went back to work.