On this week’s SELECTED SHORTS, Meg Wolitzer presents three stories that offer unpredictable life lessons, from characters who are adolescent, and those who love them—a little eccentrically.  In “The Facts of Life,” by Anthony Marra, a preteen learns about the birds and the bees from an icon of ’90s masculinity. The reader is Santino Fontana.  In “Leave Me in St. Louis,” by Tania James, sisters tap their way into a new life.  The reader is Rita Wolf.  And in Elizabeth McKenzie’s “Hope Ranch,” a granddaughter discovers that her grandmother is a road warrior. The reader is Mia Dillon.