"Do not rest your tongue on the plug as you insert it into the wall."

I get that electricity is dangerous, but are there really functioning adults hired by a company that can't be trusted to plug in a simple appliance without a safety briefing first? It seems insulting to their intelligence. Or do they make everybody do this so the one or two absolute morons don't feel bad about being forced to take the "completely basic life skills" course before they're allowed to function at even a very low adult level?