I used to wonder how or why people in New York City could (or would) listen to the National Public Radio show “A Prairie Home Companion,” and then bust a gut laughing at the jokes.  I was less surprised when my friend Jennie, from California, told me that she found the show unbearably cloying.  Why should anyone other than the inhabitants of New Ulm, Minnesota and Stoughton, Wisconsin, understand and enjoy Norwegian-and-German-Lutheran-Great-Lake-States-type humor?  Garrison Keillor whispering about the fact that right around the middle of July the vegetables in the garden get so thick and demanding that “in the bathroom, you reach for your toothbrush ... it’s a zucchini.”   There are two reasons to laugh at this: the “my life exactly” reason (Minnesota) and the “cool, a self-propelled vegetable!” reason (New York City).