A funny thing happened on the way to the checkout

  

A fresh story from one of our European readers.
I believe it's still warm. ;)

This happened just about an hour ago, on October 23, 2011, at around 13:50 CET. I decided to write about it right away so I don't forget about it.
 
I was waiting in a queue for the checkout in my local supermarket. Being early Sunday afternoon there were not many people in the store.
 
But, there were three queues for checkout. I joined the queue that seemed to have the fewest people, obviously. There were a very short lady in a beige vest and an elderly man right ahead of me. 
I had time to observe them well because the checkout employee was taking her time. Then the man dropped a few coins, and the lady ahead of me and I helped him pick them up.
 
I noticed that the checkout employee wasn't only slow but it was an employee that is usually slightly unpleasant (I shop there every single day, I am familiar with the employees) so I decided to join the other queue, on my left, that seemed to be going faster. The checkout registers are very close to each other, no more than two meters apart.
 
As it usually happens to me, the woman that was right ahead of me in the new queue suddenly had an enormous amount of merchandise that I hadn't seen earlier. Drat!, I thought and I glanced at the earlier queue, to see if it would be a good idea to return there. I noticed that there were now two or three youngsters behind the lady and the elderly man, so I decided to stay put.
 
Each of the customers from the other (earlier) queue walked by toward the exit, as there is no other way to get out, so I saw each of one of them. I was vaguely surprised that there were so many walking by - maybe four or five - because I had thought there were only two more people ahead of the lady and the elderly man. So I turned around to see how the earlier queue was progressing, and noticed that the unpleasant employee, right behind my back (like I said, the space in that market is tight), had been replaced by another one, a lady who is usually very nice and fast enough.
 
I was surprised because I couldn't figure out how this could have happened. To enter the register space and replace her colleague, the employee would have had to enter the boot from my side. She would have had to brush past me and she would have had to ask permission from the people in my queue to do so, because otherwise it would be impossible to enter her boot.
 
But I forgot all about that when I noticed that the old gentleman and the lady that had been ahead of me were nowhere to be seen! The youngsters that were behind them were still there (I think, or maybe they were different youngsters).
 
This I can't understand. 
The lady and the old man were not together. They would have had to leave the queue independently of each other - but it was almost their turn - and they would have had to walk past me, either towards the exit or towards the third queue (that was further removed from the first two registers).
 
I wasn't distracted or anything; in fact I was trying to determine which queue was being processed faster, so I was watching attentively. And there weren't all that many people in the shop anyway. Each queue had no more than five or six customers waiting.
 
I don't understand what happened. When and how did the employee replace the first one? And where did those two customers go? 
All of this happened in a matter of five minutes or so.

 
Interesting. :)
Obviously I have no idea what happened, so I can't help you with that. 

If anything similar has happened to any of you reading this, do let us know.

If you want to report a perceived dimensional anomaly, please do, but read this first.