Many Happy Returns - Having returned home after a long an arduous journey, why should the Prisoner then knock on his own front door? Admittedly the Prisoner would not have the front door key to his house on his person. But who did the Prisoner think would there to open the door? The Butler perhaps!
I read somewhere that in the original script,
the Prisoner did make entry into his house, and was taken for a burglar by Mrs.
Be seeing you