While in the Air Force, some people got a nickname that was all he was known by, even on roll call, he would answer to his nickname.
It became a laugh when a stranger would ask for him by his real name.
I had parents asking if they could see ........., No, nobody by that name works for me here.
Then around the corner comes the beloved son, and an embarrassing explanation that he is realy ...., not .... as they thought.