I went to get my baby's passport photo taken in a shop that does various photo services. I didn't book, just walked in.
When I was typing my email address in on the screen (to receive the digital files), I missed a letter off the end of my name. The man (who was evidently from a foreign country and had english as his second language) said I had missed a letter. Now, my name also works as a name without the last letter, but it's less common that way, so I presumed he just guessed that my name was the version with this extra letter.
After my name comes a number in my email address. When typing, I also missed the second digit of said number. The man said "you missed a number - it's 3 isn't it?"
Now, how did he know that the number was 3?!