Today I rented a server for the first time in my life. I ordered it on Monday, today I finally got access. Obviously, I've used #SSH many times before, since years. I know the ssh-keygen -t ed25519 by heart.
I wanted to have the server config reproducible, so I asked #claude #opus (you know, the "smart" one) to write an ansible playbook for me. (Because I've never really used ansible before.)
Within two/three hours I had gotten myself twice into a situation where I needed to access the server through some fallback method (server console in the browser). 
The reason is that I wanted a somewhat hardened SSH setup. So Claude produced a config with PermitRootLogin no. Sensible. I saw it.
I ran ansible, afterwards I couldn't log in anymore, because #Claude recommended to defer creating a non-root user account to the second step. I didn't think it through enough. That was issue 1.
The fix was simple enough:
I restored SSH access for root. I adapted the ansible playbool so that PermitRootLogin would only be set if there are other admin users. That fixed issue 1.
So I continued.
I set the config for adding the new user. It got added to the sudo group, but I didn't want to allow sudo without password. The user got it's own SSH key, the .ssh folder and the .ssh/authorized_keys had the right permissions. I ran ansible again. It worked, the new user was created. Now that there was another admin user in the config, ansible reestablished the PermitRootLogin no.
I tried to log in as the new user, no problem. I tried running sudo and... it asked for the new user's password. But the user didn't have a password. That was issue 2.
Fixing it was again simple: Log in as root (via the web console), set a password for the user.
Still, I'm quite annoyed by myself screwing up two times in so short succession. Normally I pride myself in knowing what I'm doing (in most things I'm doing).