Having done loads of tech support for old people, I've really got used to being sensitive about the terminology I used - and their 'alternative' terms.

Some of the best examples: - 'the green' for the desktop (that teal desktop background from Win98) - 'e' for the internet ("So when I'm on e...") - 'the computer' for the screen - particularly hard to diagnose over the phone

Also, several times I fell foul to the old bash.org facepalmer of physical action when I ask if they can "open a window". Skeomorphism can be confusing.