Oh, but they can! If you had told me, I never would have believe that Shaquille O'Neal could ever do a windmill spin. I wouldn't believe he could have done it when he was young and strong, much less at his current age (he's two months younger than I am) and decrepitude (he's starting to get the Kareem Shuffle thing going).
Well done Shaq!
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Totally unrelated YouTube silliness: My generation's answer to Ian Anderson -- The Beatboxing Flautist (doing the Mario Bros. theme, no less).