Nick Dow quoted
> Nothing can be fool proof, because fools are ingenious.

Here's a variation on that which seems worth quoting, albeit that it is highly politically incorrect. It came from a late boss of mine, applying to the design of medical equipment. "You can make it foolproof. You can even make it bloody fool proof. But you can't make it nurse proof."

Behind that is the sad truth that nurses are often overworked and under-trained for the tasks that they are expected to perform. RTFM does presume that the M is even available.