I had this conversation recently with a lady who swore she had been using computers since forever.
Tech Support: "All right. Now click 'OK'."
Customer: "Click 'OK'?"
Tech Support: "Yes, click 'OK'."
Customer: "Click 'OK'?"
Tech Support: "That's right. Click 'OK'."
Customer: "So I click 'OK', right?"
Tech Support: "Right. Click 'OK'."
Pause.
Customer: "I clicked 'Cancel'."
Tech Support: "YOU CLICKED 'CANCEL'???"
Customer: "That's what I was supposed to do, right?"
Tech Support: "No, you were supposed to click 'OK'."
Customer: "I thought you said to click 'Cancel'."
Tech Support: "NO. I said to click 'OK'."
Customer: "Oh."
Tech Support: "Now we have to start over."
Customer: "Why?"
Tech Support: "Because you clicked 'Cancel'."
Customer: "Wasn't I supposed to click 'Cancel'?"
Tech Support: "No. Forget that. Let's start from the top."
Customer: "Ok."
I spent the next fifteen minutes re-constructing the carefully crafted setup for this lady's unique computer.
Tech Support: "All right. Now, are you ready to click 'OK'?"
Customer: "Yes."
Tech Support: "Great. Now click 'OK'."
Pause.
Customer: "I clicked 'Cancel'."
And people wonder why my mouse pad has a target on it labeled "BANG HEAD HERE."