In the beginning, there was the keyboard. If you wanted to issue a command to your computer, you typed it. Then came the Apple Macintosh, which popularized the mouse as standard equipment. No longer would people have to memorize key commands! No longer was the computer a plaything of the geeky intelligentsia! The menus would list all available commands, and the mouse would choose them.

Even Apple, though, hedged its bets. Nestled on either side of the space bar were keys not found on any typewriter. They were modifier keys, to be used exclusively for keyboard shortcuts, aimed at those who still found tapping keys to be more efficient than mousing to the menu.

To this day, some people live by keyboard shortcuts—on Windows it’s Control C for Copy, Control V for paste—and others use the mouse. Each looks at the other with disdain.

As a member of the former group, I think a lot about the mnemonics of keyboard shortcuts. Your English keyboard has 26 alphabet keys, plus four or five modifier keys. (Their names differ on Mac and Windows, but it’s some combination of Shift, Alt/Option, Ctrl/Command, Control, Windows and sometimes Fn.)

These shortcuts have to trigger dozens of commands in an infinitude of programs. How can anyone keep them straight? It helps that Apple came up decades ago with simple combos for the most important functions across all programs. While pressing the Command key, you press the first letter of Print (P), Bold (B), Italic (I), Underline (U), New (N), Quit (Q) or Save (S). Microsoft later adopted the same sequences (using Ctrl instead of Command), so that they’re now universal on all computers. Thank goodness for copycats—I mean, standards. But Apple also came up with Z for Undo, X for Cut, C for Copy and V for Paste. They’re consecutive keys on the bottom row, but otherwise not so memorable.

Here’s the logic that Macheads used to explain those mappings. “Well, Z, the last letter because it Undoes the last thing you’ve done. X for Cut because X looks like a pair of scissors. And V for Paste because it looks like the proofreading mark for ‘insert.’” Well, okay.

Things break down when more than one command starts with the same letter. Most of the Windows logo keystrokes on a PC are straightforward: E for Explorer, L for Lock. But what about the Start Dictation command? It can’t use S, because that’s Search; can’t use D, because that’s Display Desktop. So we get Windows H—a letter that doesn’t even appear in “Start Dictation.”

I guess keyboard shortcuts are on my mind lately because of a massive mistake Apple made in 2015. It goes like this:

If there’s one keyboard shortcut that’s nearly universal, it’s the space bar to play or pause a video or audio. It works on every video site (YouTube, Netflix, Hulu ...), every editing program (Movie Maker, Final Cut, Premiere, Avid ...), every photo app (Google Photos, Amazon Photos, Flickr, iPhoto, Windows Photos ...).

But in 2015 Apple introduced a new Mac Photos app. In this program, the space bar did not mean “play video.” There was no keyboard shortcut for “play video.” Instead Apple had mapped the space bar for opening a photo thumbnail to see it at full size. To play a video, you had to move your hand from the keyboard to the mouse or track pad. This from the company that invented the space bar playback convention! (Fortunately, in the latest version of Photos, the space bar once again means “play/pause.” Now, to open or close a photo, you press the Return key. It’s taking me some time to adjust, but with therapy, I’m getting there.)

Truth is, you don’t have to settle for the mappings Apple and Microsoft have come up with. You can change almost any Mac keyboard shortcut to whatever you want, and free programs let you do the same in Windows. These days it’s your problem if the keystroke is awkward. But anything’s better than lifting your hand to pick up the mouse. Who wants to do that?