By not testing it properly before running it over the whole file system resulting in a few hours of extra work cleaning up the mess I made.

Very true. I used to do magic with xargs when working as a sysadm. Also a good way to mess up on a grand scale. Ask me how I know.

What’s this weird obsession with measuring everything in anything but metric? How am I supposed to know how much a rhino weighs?

Had they said 1500 - 2500kg it would have been clear as day.

But on a positive note I now know how much a rhino weighs.