It seems I wear out mice. While I use keyboard and mouse in combination, I still spend a lot of time behind my computer and that amounts to a lot of clicks. And both keyboards and mice are part-mechanical things — which can wear out before any of the electronics do.
Yesterday my mouse was acting strange. Sometimes a click just didn't register. Now that can happen on an overloaded system, or when it's thrashing, so it took a while for me to realize that the problem was only with left-clicks, and it occurred even when the machine wasn't thrashing. And sometimes, instead of a click not registering, it became a double-click — kind of awkward when you try to click on a title bar to bring a window forward: suddenly your tiny window takes over the whole screen. And then, of course, you need another double-click (or at least a click) to get that window back to its normal size. I even rebooted the machine (something I hate to do), but found it made no difference: the mouse continued to ignore clicks or doubling them. Then I found that sometimes, when I clicked the mouse button a little bit higher than where my finger normally rests on it, it was… more likely to register a click. And the right button (used much less) behaved quite normally.
That was it — there's no way I was going to move my click finger every time just to make it more likely it would actually result in a click (or an unintended double click). So I ran out to buy a new mouse, even though I had planned not to go out at all — it was so cold! I dove into the very first electronics shop I came past, and they had what I wanted: a small, wireless mouse (“for notebooks”, but those fit my small hands better). No weather to go shopping around for a cheaper one, and this one even comes with a three-year warranty.
Amazing that it feels so good that a light click, anywhere on the mouse button (including where my finger normally rests), just — clicks! That feeling will wear, no doubt, but yesterday, and today, I'm still really enjoying this little piece of utilitarian hardware. And it's not even shiny, but (deliberately) an elegant matte gray-and-black, so it's a pleasure to look at, too.