If you hook a dog leash over a ceiling fan, the motor is not strong enough to rotate a 42 pound boy wearing Pound Puppy underwear and a Superman cape. It is strong enough, however, to spread paint on all four walls of a 20' x 20' room. Brake fluid mixed with Clorox makes smoke, and lots of it. If you use a waterbed as home plate while wearing baseball shoes, it does not leak. Legos will pass through the digestive tract of a four year old.
Super glue is forever.
McGyver can teach us many things we don't want to know. No matter how much Jell-O you put in a swimming pool, you still can't walk on water. Always look in the oven before you turn it on. The spin cycle on the washing machine does not make earth worms dizzy. It will, however, make cats dizzy.