Sometimes it happens this way: You’re 9 years old in the fourth grade and your stern-but-fair teacher Miss Ruth Ferris has had the remains of an old paddle steamboat hauled onto your school grounds a little ways off the Mississippi River in St. Louis. She does so partly for fun, and partly for the sake of instruction and storytelling on the ways and boats and people of the river, which she reveres. You stare at the boat in awe, climb up into its pilot house, run your fingers over its paddlewheels—and you feel something taking root in you. You don’t…