I know how to do the Paris Metro.
I know how to use the ticket machine so I don’t have a line of impatient Parisians behind me while I struggle with whether I am going to acheter a single ticket, a carnet of ten or a trip to Disneyland Paris. I know where to put the notes, in the machine next door with the picture of the euro notes, not my machine with the picture of the credit card.
I can tip tap up and down the worn concrete steps with the best of them, and I know from experience that if you aren’t going to tip tap up and down the escalators with the impatient Parisians, you will stand to the right.
I know how to work out which line and which direction to take so I end up at Notre Dame, not Versailles
So why did we take a taxi to the airport?

And that’s why we took a taxi!!