Everything in our world is about convenience: saving time because it’s priceless. Thus, the invention of keyboard shortcuts doesn’t really come as a surprise, but I’m still very grateful to whoever came up with such a concept (probably someone who didn’t like using a mouse). Most are pretty conventional, such as ctrl + i for italicise, ctrl + s for save, ctrl + n for new file/folder, so on and so forth. Substitute “ctrl” with “command/apple” key for Macs. So I never really understood why ctrl + z was undo, instead of something like, say, zip the file. I know ctrl + u is underline, so that’s taken, but why not make the underline shortcut ctrl + shift + u, and use ctrl + u as the shortcut for undo? Then it clicked: the “z” key is closest to the ctrl/command key. Hence one doesn’t have to stretch one’s fingers allllll the way over to the “u” key and waste all that energy and effort. What an ingenious decision!
Still, there are downsides to ctrl + z. Sometimes when I write or draw something on paper, and make a mistake, I catch myself doing the “ctrl + z” motion with my left fingers. It’s a big disappointment, especially when nothing happens. Oh well. If even real life could be controlled by shortcuts, everything would get too fast, and I won’t be able to catch up with myself. Otherwise, I love my keyboard shortcuts. Especially in Photoshop.