Years ago I worked in a call centre doing technical support. Usually for dial-up internet providers.
I'll never forget one lady who called in. I don't remember what her issue was, but I started walking through troubleshooting:
Me: "Ok, please double click on 'My Computer'"
Her: "With my left mouse button or my right button?"
Me: "With the left button"
Her: "Ok"
Me: "Ok, now if you could double click on 'control panel' please."
Her: "With the left button or right button?"
Me: "Oh, yes, with the left button. When someones says 'double click', they are always referring to the left button"
Her: "I don't care, I want you to tell me every time what button to use"
So I did.
For the rest of the conversation, every single time I asked her to double-click on something, I would pause and say "With the left mouse button", as if that was something unusual. She complied, but I could tell by her tone that she was getting frustrated with it. She never said that I could omit the added instruction though, so I just kept going.
Eventually the problem was solved and we disconnected. Nothing came of it, but I hope the next support desk she spoke to didn't need to explain it to her again.
Sometimes you have to be very exacting with your instructions when on the phone with someone. Assuming they know which button to double click often leads to 20 minutes of you pounding your head against the desk only to realize that they've been double right clicking the entire time.
Example - One of my guys was on the phone with someone for an hour trying to figure out why their USB port wasn't working only to figure out the caller was plugging the USB drive into the wrong PC.