Imagine you had a visitor, a time traveler from the 19th century or even from earlier times. How would they perceive our world today?
Imagine you went shopping together with them.The first shock would come as soon as you arrived at a shopping centre. They wouldn't be accustomed to anything like the things we have today. They would probably be astonished, even shocked by the sizes. But if you ever have a time traveler visitor from those past times, please do take them to one of them real huge Tesco's or Sainsbury's, them big shopping "malls". Let them see the real world of our days in its glory. In their days they only saw much smaller shops.
And after browsing through the shelves of each department, you might want to approach the checkout.
"Paying by cash or card?" - the cashier asks.
Our time traveler looks puzzled. They don't know how much an Ace, a King or a Queen is worth.
Never mind. You pop your card in for them.
"Enter your pin, please."
They look more puzzled, but imagine if after the initial hesitation they took out a needle case from their pocket and a pin from out of it.
Then it would be the cashier's turn to look puzzled.
"No, I mean enter your PIN number, please."
And then it's gonna be your turn to explain that,
"PIN stands for personal identification number. So 'PIN number' as you said would stand for 'personal identification number number'. What should we enter then?"