Every once in a while, even a seasoned Mac user stumbles across a built-in feature that they never knew existed. For me, it happened most recently as I was switching applications using ⌘-Tab — something I've done thousands upon thousands of times. I've long known that multiple presses of tab will select the next app to the right. To reverse the direction, there are options: either add a Shift modifier or press ⌘-`.

It may have been the lower profile of the Magic Keyboard, or it might have just been clumsy fingers, but as I reached for the backtick, I missed and hit 1 instead. The switcher and most of my windows vanished! Suddenly I was in Mission Control's "app windows" mode, but I was baffled as to how I got there, since ⌘-1 doesn't usually trigger it.

I had inadvertently discovered that application switching and Mission Control are more closely linked than I'd thought. Not only was this hotkey deliberately placed near the keys used for app switching, but tab and backtick cycle apps within Mission Control regardless of how it is invoked, including by ⌃-Down Arrow or a swipe gesture.

This doesn't seem to be documented in any Apple support materials. I began looking around the web and found that, of course, I wasn't the first person to notice ⌘-1. Bite-size tips and tricks articles on Mission Control or the app switcher often included it. But how was I to find those before I already knew what I was looking for?

When I was a kid, I devoured massive tomes like The Macintosh Bible and MacWorld's Mac Secrets from cover to cover. It wasn't always thrilling reading — I remember questioning whether I really wanted to slog through a chapter on printers — but my early completionist instincts kicked in. Each book was comprehensive, if not exhaustive, and full of gems like the ⌘-1 trick. I learned a lot because I knew that I was getting the full picture.

Today, especially with the demise of Mac OS X Hints, there's nowhere I can turn for definitive coverage of hidden features. This is one more reason why user interface designs are often criticized if their features aren't discoverable. The "-able" suffix here does not imply "by any means"; after all, I discovered ⌘-1, but purely by accident. In the past, I would have had a second chance at discovery (or more accurately, learning), even if it meant checking out a five-pound book from the library. Now, I have to rely on good design, and in its absence, happy coincidence.