Okay.. I just did it. I had to reinitialize a server because I lost the single SSH keypair (probably the one from my BELOVED Windoze desktop that I recently had to reinstall) that was authorized to access the server, and I didn't add any of the other clients' keys to the server's authorized_keys.

Note to self: replicate all your fucking keys or (or rather, and) back them the fuck up into your keychain already!! Why else does that keychain USB stick exist, Condor, you bloody fucking moron?!!

Well, at least now the admin panel on Aruba Cloud doesn't say "Ubuntu 14.04" that's been upgraded to Ubuntu 18.04 anymore, but 18.04 as it should.. but that's about the only good thing.