Yet another note to self on how to fix things in Ubuntu after a fresh install, found at askubuntu, this time to remove the standard bookmarks in the Nautilus file browser. I use a different setup of folders, and don’t really need these unused bookmarks. I wish it could have been easier to just right-click and delete to remove them (like for your own bookmarks), but it turns out to be a bit more tricky.
The default bookmarks are actually built from ~/.config/user-dirs.dirs, and this file is rebuilt on login from /etc/xdg/user-dirs.defaults. So it is necessary to modify both of the files, which may most easily be done with:
nano ~/.config/user-dirs.dirs
sudo nano /etc/xdg/user-dirs.defaults
In the nano editor you should comment out the ones that you don’t want.
And after a login the bookmarks are gone.