Absolute Adjective Maniac

The other day in the English office, Young Allie became very excited when she realized she knew something I didn't-- this kind of silliness among the new teachers happens for a few years, until they scratch through the thin veneer of my intellect and realize there's a soft brown stupid underbelly to my brain, a crappy underbelly full of gaseous holes-- anyway, she read that English speakers unconsciously follow a rule that "absolutely" stipulates the order of adjectives . . . I had never heard about this claim that Mark Forsyth makes in The Elements of Eloquence, and I was properly deferential and fascinated by Young Allie's interesting piece of grammatical information; Forsyth believes that:

"adjectives in English absolutely have to be in this order: opinion-size-age-shape-colour-origin-material-purpose Noun . . . so you can have a lovely little old rectangular green French silver whittling knife, but if you mess with that word order in the slightest you’ll sound like a maniac . . .”

but after thinking deeply about this rule, I think it might be a great big brown steaming fresh shit pile (a sequence which does begin with opinion and size, but then inserts color before shape and age . . . and 'soft brown stupid underbelly' doesn't follow this rule either . . . so you probably shouldn't use the words "absolutely" and "maniac" when you're talking about English grammar . . . I have a feeling H.L. Mencken would kick this guy's ass).