Found out the hard way that if you edit /etc/sudoers with anything other than visudo you best be absolutely sure the syntax is correct, otherwise sudo will refuse to read it and you’ll be locked out.
Also learned to add -rf to the rm command at the end, after I re-read it to make sure it does what it should do. Something like rm /path -rf instead of rm -fr /path. That protects you from your fat fingers hitting the enter key half way through.