A Size Trial

I have made a shopping error.
I am not proud of it but I offer it up for your judgement.
First a little background.
I tend to buy medium.
And I don’t mess around.
I saw it in the window. I tend only to buy things that are in windows as I always know they will have at least one in stock. Over the years, I have paid for more display models than Rod Stewart.
Within two minutes I was at the till having spotted a Medium, solicited the opinion of the Portuguese shop assistant and was at the till entering my PIN number before catching up with the friends waiting outside the shop whom I had not informed of my intentions after seeing the item in the window.
With me so far?
Good.
As I walked along I found I had chosen the wrong size (I wore it to go and it felt loose).
How? Surely I could not need a Small. I have never bought small clothes. It creates an arms war and exposes my long wrists and cheap watch to public ridicule.
I returned home, looked again at the crumpled label and saw my M (for Medium). Then I uncrumpled it and noticed something else. Above the M was an S. And below the M was an L. And below the L was an XL.
And the XL was in RED.
Hmmmmmm.
Being about the leave the city realised I had 90 minutes left to get back to the shop and exchange the item. I was back within 20 minutes to spare with a Large jacket and a small voice in my head.
Tell the world, it said.