They say that even a stopped clock tells the right time twice a day - and maybe the same is true of conspiracy theorists.
David Icke, the former Coventry City goalkeeper turned peddler of far-fetched ideas about the humanoid reptilians that run the earth (from George W Bush to country singer Kris Kristofferson), has long been derided for his preposterous allegations against ruling elites.
But when the 60-year-old takes the stage at Wembley Arena tomorrow for what is being billed as his biggest ever live show, including a full nine hour lecture, he might well feel a little vindicated.
For while Jimmy Savile may have been protected by the BBC and the media establishment, Icke has been calling the former DJ a paedophile for years, to anyone who would listen.
“They used to laugh at David Icke,” claims the promotional material to his Wembley show, and indeed they did.
This dates dates from his appearance on the Wogan show in 1990 when he claimed the world would soon be devastated by tidal waves and earthquakes, after a chance meeting with a psychic healer that had the unforetold consequence of ruining his career as a sports journalist - something he had turned to after being forced to give up football as a young man.
“Now they come in their thousands all over the world to see him,” the literature continues. “Who are we? Where are we? What is reality?”
The ellipsis on Icke’s website read with the ominous intent of the Eastenders drum riff: “Who controls the world and dictates our daily lives...and to what end?”
Even fans of Icke - and there are thousands - are unsure what to expect. Many who can’t make it to Wembley Arena will be watching online.
“I am going to spend the best part of ten hours connecting a vast number strands and dots,” he said. “Only when you do that can the picture through which daily experience is happening can be seen.
“If anyone’s going to watch on the net, it’s not something you can dip in and out of, because if you do you’ll lose it. The true volume of context can only be seen if you watch it from start to finish. It is a story. It is layering and layering and layering information until the tapestry can be seen. The tapestry is fantastic.”
If his views on Savile are anything to go by, the tapestry will be highly libellous. That the Savile secret remained hidden for so long, he claims, is to do with 10 Downing Street and the Royal Family - both long established bastions of Satanism.
“When you start there’s strands and there’s strands and there’s strands and eventually it builds up,” Icke claims. “People are looking at concepts that in and of themselves people would think, ‘You are nuts mate you are having a laugh!’ But then when it builds up you understand why it makes sense, why it’s true.”
Of course, the epistemology of the conspiracy theorist is unfalsifiable, therein lies its appeal.
If you don’t believe MI6 killed Princess Diana, then for Mohammed Al Fayed, you too are MI6 and the debate is over.