It's remarkable that McGoohan got a free hand with this project. I'm not sure if an actor today would have the freedom to lay out his vision in such a way.
What is an individual?
McGoohan’s series hooked a mass TV audience with its intelligent, clever, thrilling and entertaining scripts. Each episode was an event that left the audience either bewildered and angered, or enthralled and inspired. This was part of McGoohan’s intention, to create debate, have the viewers question their own reality. As McGoohan put it in this interview:
http://dangerousminds.net/comments/we_are_all_prisoners_patr...
And the the book that accompanies that interview "The Prisoner Puzzle" can be found here:
It does come come with interpretations for all of the 17 episodes which some might consider spoilers.
McGoohan forbad anyone on the crew to mention television or that they were working on a TV show while on the set. He felt that if people thought that they were working "only for TV" then they may be tempted to compromise on quality.
So many old beloved TV shows just look really bad on a modern TV, and can be hard to get back into. (I never have that problem with old black-and-white movies, for some reason.)
Today it looks better than most films. Thrilling.