Updated June 12th, 2019.
One could argue that Undo, Cut, Copy, and Paste are the menu items that make a Mac a Mac. They are always in the Edit menu, and every program uses the same keyboard shortcuts for them:
- ⌘-Z for Undo
- ⌘-X for Cut
- ⌘-C for Copy
- ⌘-V for Paste
Guess what? The keys are right next to each other, in the bottom row of the keyboard. That should make remembering them easier.
I don’t know how they came up with the Z for Undo, but that’s OK. I do have some ideas for X, C, and V but only if you ask.