How to force emacs projectile to reinitialize a project?

I'm using projectile with emacs to manage a large project.

I moved a number of directories with scores of files.

The old file paths are still showing up in projectile find file (C-c p f).

How do I remove them in bulk or force projectile to re-initialize the project?

I've tried:

• projectile-purge-dir-from-cache
• projectile-invalidate-cache
• quitting emacs, deleting ~/.emacs.d/projectile.cache, restarting emacs
• adding a .projectile file with 'exclude' options for the original dirs

After all of these, the same original list of old paths/files still appears on C-c p f.

C-u C-c p f does it.

Thanks to Daimrod!