Here's a cockup:
About a decade ago I had to get some X-rays done because I have the back of a coal miner. Upon entering the hospital the receptionist scanned my ID and made the remark
"oh, how fun, you were born here!"
Which is not the case, I was born in a different hospital. But this was the sign for me to dig deeper into what data this hospital keeps of me. I was not prepared for what I was about to hear: she told me
that I was my father. Yes, you read that right. She read the name and date of birth of my father out loud, and he happened to be born there.
Then I was like:
oh wow funny file mix-up haha, can you imagine. But she was dead serious and just went like:
no, you are [my father's name]. I was baffled. I said:
hold on, lady.... first of all: here is my ID, the one that you have just scanned. Look, that's my face, and that's my name. I'm pretty sure that I know who I am. Second, take a look at my dad's DOB and then take a good long look at me... do I look like I was born in the early 50's? (I'm from the early 80's). I would look ridiculously good for someone who is about to hit retirement age, not? And third and foremost: my father... he's deceased just over 17 years ago. If I would be my father, then that would be some Jesus Christ resurrection type of miracle, wouldn't you say?!
And then, with zero irony or emotion, just with a deadpan delivery, she said the infamous words:
but the computer says it right here that you are [my father's name]. And that was final. An awkward silence ensued.
Literally this meme, folks:
I swear, some people are not sentient.
Long story short: she didn't give in and I had to get my spine checked as my dead father, which is messed up on so many levels.
I explained this extraordinary ordeal to the doctor who analyzed my X-rays and he let out a sigh, as if it wouldn't be the first time the receptionist enabled some monumental cockup. Then the doctor processed the corrections himself in the system, and apologized to me for any inconveniences. So it all ended well.
But damn.... just, damn!
www.bbc.co.uk
Poor guy!
I did, however, had the pleasure of watching someone frost a cake and lick her fingers during the process while I was in line. That was the last time I ever went to a cafeteria style restaurant. 
