From the "Learn from my mistakes" department:

GNU/Linux command line programs are very powerful things that happily do exactly what you tell them to.

So, when I decided to move all the files from subdirectories into the next directory up (while re-organizing a collection of videos I've made over the years) I used the following command:

mv ./*/* ./
(move all files from all subdirectories in the current directory into the current directory)

I really should have made use of the following command first:

pwd
(print working directory, ie. what is the current directory?)

since, as it turns out, my current directory was not ~/Videos/projects/raw, but was instead ~/

ouchies.

Just hoping to spare you my pain =^_^=