It's easy! Just :!reboot!

I usually edit the file I want then save it on an external drive and proceed to perform a clean install of the OS

Pull the plug. Unless you're on laptop, in that case you gotta wait a few hours.

"I've been using vim for 15 years!... Because I can't figure out how to close it."

Blazingly fast while doing it!

What you do is you accidentally save the mistake you just tried to fix, have no idea what else was changed, and accept your fate.

Everyone tells me they can't exit vim, while I think "Why would you?".

Shift+ZZ is :wq iirc (write and quit)

You enter two Mortal Kombat fatalities.