If you're a grownup of a certain not-so-advanced age, there's nothing to make you feel ready for the cultural glue factory like MTV's stunt-comedy show Jackass. You see its young male pranksters riding and crashing shopping carts; getting turned upside down in a sloshingly full portable toilet; swallowing a goldfish and puking it into a bowl; dressing up like a disabled person and getting pushed off a wheelchair. And you think--and you know how this sounds even as you think it--This is funny?
Which is to say, you have entered the environs of Knoxville--as in Jackass star Johnny Knoxville, the...