Hi Dien...

Yes, I see your point about the Dummies books. The Madden/Ace thing is a little different -- The books are advice FOR "dummies" [presumably from/by experts].

-- Conversely, with Ace Hardware, Madden seemed to be saying, "*I* am a dummiy, so take my advice [?!?!?]" -- in other words, it was advice *from* a dummy!!! -- which makes no sense.