@b0rk
To be honest, I never got over this fear unless I'm on a Pi, where I know I can re-image the SD card. But on a server? I still freak out when I have to copy files. I'm double or triple checking every potentially destructive line, then explaining it to a rubber ducky, before hitting enter.
@CleoQc not clear where the line is between reasonable caution and paranoia (we all need a little paranoia on the command line!)