Mucked up disablement of Notifications Center Tried to disable Notifications Center and remove it from the menu bar, unfortunately didn't copy the whole command:

launchctl unload -w /System/Library/LaunchAgents


Now I'm presented with a completely black screen when I login, and

launchctl load -w /System/Library/LaunchAgents


doesn't seem to help. What should I do now?

Rebuilding the user account didn't work.
From the launchtl man page, it looks like it might need the -F parameter to force loading.

launchctl load -wF /System/Library/LaunchAgents

I can't tell if it needs sudo too, though it might, as the LaunchAgents folder is root:wheel rwxr-xr-x