Maybe at some point you set LANG=en_US.UTF-8 and LC_ALL=C
because you read somewhere that C had faster sorting than en_US.UTF-8
(somewhat reasonable when you're dealing with large amounts of data).
and you set it in zshenv.
Maybe you then also start to wonder why your prompt gets messed up when you use
»
Also you wonder why emoji and other things don't work in your terminal
and you see a string of <f0><9f><98><80> or ???? ???? or similar
Wonder no more! set LC_* back to en_US.UTF-8