Wilson will be remembered for a lot of things, but what sticks with me most is his "Strange Loop" theory, which goes something like this:
Any conspiracy big enough and powerful enough to hide most of the evidence relating to its existence -- like the supposed conspiracies behind the murder of JFK, or the Holy Grail, or the Holocaust, or the alien/human hybrids -- is also powerful enough to manufacture the evidence that led you to believe in that conspiracy in the first place.
It's a nifty little bit of logic, and therefore almost wholly useless against your average conspiracy freak, who left logic buried in an unmarked grave in the desert a long time ago. But there's a corollary to the Strange Loop:
In other words, "they" only let you know they exist because they wanted you to know they exist.
That kind of thinking tends to send a conspiracy junkie right over the edge, so use with caution.