Adventures at the SuperMarket (MiniMall)

The supermarket is one place where you bump into German people with whom otherwise you would not interact much. I had some interesting experiences at the MiniMall a popular German retail market chain in Endingen.
You entered the supermarket with a push cart in which you dumped all the stuff that you intended to buy before checking out at the cash counter. The supermarkets had an intricate way to make sure that the push carts were replaced at their original place after use and not scattered all over the supermarket frontyard. All the push carts were qued up in a line, each one coupled to the other through a locking mechanism. You could extract a cart from the que by inserting a low denomination coin which would open the lock and you could later get back the coin when you placed the cart back to the que after shopping.
I was under the impression that the slot in the push cart took only one and half euro coins just like the cigarette vending machines did.
One fine day I was at the supermarket and was about to remove a pushcart from its que when I noticed that I didnt have the correct denomination coins, only small loose change.
Desperately I tried to get my 5, 10, 20 cent coins exchanged for one or half euro coins which I thought would allow me to extract a push cart for my shopping spree.
One old gentleman looked at me with disgust as I thrust the loose change I had towards him. At that moment I didn't understand why he should be so offended.
Anyways, he gave me a couple of half and one euro coins but without accepting the equivalent 5, 10 and 20 cent coins I had with me.
Gleefully I went over to the pushcart que, inserted the coin and got my pushcart.
It was later I realised that the locking mechanism in the push cart que also accepted 5, 10 and 20 cent coins.
No wonder the venerable gentleman who had handed me the one and half euro coins was not happy with me. Most probably he took me for a beggar!