Explain The Prisoner ... yea, people've been trying to do that for 37 years now.
Yes, it's all about control. That part is obvious. After all, No.2 wants information, information, in-formation. But the question is, who's doing the controlling? (Who is No.1?)
Depending on whether you take the series as an action spy series, an analogy, political commentary, or a Christian allegory, you can come up with lots of answers.
For instance, in Change of Mind society tries forced Social Conversion on No.6. Is society the oppressor? In The General regimented learning is the control de jour. Maybe it's the schools. In Free For All everyone votes for No.6 for No.2's job, but it's a sham, the new No.2 takes control regardless and No.6's disabling the security system prompts nobody to escape. After all, in a democratic republic, the oppression you endure is the oppression you voted for.
Each No.2 tries a different trick; No.6 never gives up, and sometimes wins, but he never gets free either. All the different controls on us, but who's running the show?
In the end (Fall Out) of course a very unusual thing happens which I won't spoil here (the web has plot summaries if you want them) but the upshot is: who is it that controls us? Us. In the allegorical sense of The Prisoner, we're all each responsible for our own sin and doom. The prison we're in is of our own making.
Those are all possible answers. There are others. No answer is "the" answer. Certainly Patrick McGoohan has never come out and said "I meant *this* interpretation and not *that* one."
Besides, answers are a prison for oneself.
Thats a very good interpretation.
One of the great things about the series is that it actually engaged your mind.