i messed up really bad

so I was trying to change the name of my friend's main home folder (idk what it's called) to dildohitler, from michaelhoffmann. I know his password and everything so I enabled a root account and logged into it from terminal.

Here's where I messed up. This is what I typed into terminal:
mv /Users/michaelhoffmann /Users/dildohitler

now the "michaelhoffmann" folder is no where to be seen. I tried to fix it and typed in this immediately after:
mv /Users/dildohitler /Users/michaelhoffmann

but I cant see that anything happened.

PLEASE HELP.

I know I am really stupid.

Why were you trying to change the home folder? And that too to an offensive name as that? Surely your friend didn't ask for this? If you know this password, there must have been some level trust that you wouldn't do such silly things..

Once you "mv" a folder to the new name, the old name is obviously not going to show up. However, you should be able to "mv" the new folder back to the old folder name unless you are not typing the names properly..

Nothing we can add about the stoopid part. Never interfere with the Home folder. This is precisely why we often recommend keeping others out of your computer and keeping your password confidential and safe.

Michael may well up for downloading a new version of his operating system and doing a clean install if Ashwin's recommendation is not successful.

Go to /Users in Finder - what do you see? Something has to be there because you didn't do anything that would delete content.

As an aside, I'm sure you've learned the lesson but I feel it important to say any way: people have a lot of important content on their computer, much of which may be very important to their career/education and to have this tampered with is terrible. Please consider never doing something like this again.