Noble, doomed enterprise, volume 3. The good people at QI (they're Brits) have published a third foray into the wilds of Ignorance, doing battle with falsehoods, half-truths, and other forms of deception, but whether in the fullness of time their battle to rescue truth from illusion will succeed, I would not bet the farm on it. As the poet said, "Man hears what he wants to hear and disregards the rest." But don't disregard this enlightening book. Good for one's self-esteem, as well as pub quizzes.
No, it doesn't take half a year to read. One week would suffice unless one keeps it in that unofficial reading room where the episodic nature of the book's entries fits nicely with the business at hand.