I accidentally untarred archive intended to be extracted in root directory, which among others included some files for /etc directory.
I went on to rm -rv ~/etc, but I quickly typed rm -rv /etc instead, and hit enter, while using a root account.
I hand-edited sudoers.conf day one on the job without using visudo
So in one day, I learnd both how to move a volume from one AWS VM and that there’s no good reason not to use visudo.