The Guy In 7B

Nobody knows the name of the guy in 7B.
What little mail he gets is addressed to Resident or Occupant.
He must have a post office box somewhere in the city.
If you walk up to him and introduce yourself, he’ll say “Yes, I know you, how are you doing?” but not introduce himself back.
I did a search online, but there’s nothing about him.
Don’t bother trying to look through his trash. He shreds everything beyond recognition.
The super won’t tell me.
So, I called him 7B.
“How did you know my name?” he screamed.
And promptly moved out.