> I prefer using the mouse mostly because I cannot remember all of the shortcuts in a range of different environments.

This is why one of the greatest changes in power user tooling in recent years is the "find anywhere" hotkey, which is now available almost everywhere.

Mouse interaction is slow and hardly a panacea for finding features buried in menus. "Find anywhere" type interactions with fuzzy search allow you to use they keyboard and highly mnemonic abbreviations to turn up what you're looking for. With a few exceptions, I tend to lean on them even for things that I use regularly, because it's easier to learn which few keystrokes will turn up the option I'm looking for than it is to rebind a fresh hotkey in each environment or, as you say, memorize the built-in one.