Why 'The Prisoner' Endures - WSJ.com

Eventually tiring of the John Drake role, Mr. McGoohan was able to persuade his British boss to bankroll a series in which a Drake-like character would explore more meaty themes. He delivered a libertarian classic, somewhat marred by the hurriedly written final episode in which Mr. McGoohan's character leads the Village's other inhabitants in a successful revolt. He finally confronts Number One, who is wearing a false face. When that is yanked off, a monkey mask is revealed. And when that is also pulled off, the face of Mr. McGoohan himself is seen.

As Mr. McGoohan told close friends, the implication is that Number Six had willed himself to think like a prisoner, limiting his options even while he sees himself as the ultimate rebel. The answer given in every episode to his question about who Number One is thus could have a double meaning. Perhaps it was meant as: "You are, Number Six."