I work in a small mobile phone repair and accessories shop.
One afternoon an older gentleman and his wife came into the shop carrying a plastic shopping bag that looked like it had a box in it.
Client: Our phone isn’t working.
Me: (imagining they have been given a new mobile phone by well-intentioned family) Ok, what’s the matter with it?
Client: We can’t make or receive any calls and it’s very inconvenient.
Me: Ok well I’ll take a look at it, maybe there’s something wrong with the network settings.
They open the bag and dump onto my counter a “wireless” landline phone complete with cradle.
Me: This is a landline phone.
Client: *blank stare*
Me: I work with mobile phones.
Client: Well it is mobile. It’s one of those cordless ones that you can walk around with in the house.
Me: Well, yes, in that sense. But it’s still a landline phone. I can’t fix it.
Client: (looking equal parts annoyed and desperate) But we NEED to be able to make calls!
Me: Have you tried replacing the batteries in the back?
Client: Do you sell those?
Me: … No. But your local supermarket will – they’re standard AAAs.
Client: Why don’t you sell them?
Me: Because this is a mobile phone shop and mobile phones don’t use standard AAAs.
Client: But this IS a mobile phone!
They might have said more, but I didn’t hear them over the banging of my head against the desk.