Twenty years ago,back when dial up modems were still a black art, and you had to type in AT commands by hand at a prompt to connect to a network, I was talking a client through the process of logging in. The fact that it was the last day of
my business trip, my flight was in two hours, and this person had _never_ used a computer before were adding to my stress.
Me: Now, you have to input all of this part in capital letters.
Client: What are capital letters?
Me: Don't worry. we'll get someone to talk you through it by phone.
(which took eight hours!)