Funny passage from The Final Days by Woodward/Bernstein...
"The President was almost totally lacking in mechanical ability and was not well coordinated physically. After four years of handing out souvenir presidential favors of cufflinks, tie clasps, pens and golf balls, Nixon still required assistance to open the cardboard boxes. Bull(Stephen, a personal aide of the President) was accustomed to providing such help. Once, the President had called him in to open an allergy-pill bottle, which Nixon had been struggling with for some time--the childproof type of bottle, with instructions saying 'Press down while turning.' The cap had teeth marks on it where Nixon had apparently tried to gnaw it open."