FIU'S BIGGEST DONOR WAS A BOY WITH HOLEY SHOES The man who pledged FIU's single largest donation is filled with ideas and energy, yet he hasn't forgotten the tattered shoes of his boyhood. BY GEORGIA TASKER Herbert Wertheim is an inventor, pilot, philosopher, philanthropist and university trustee. He also is a charming storyteller. ''Telling stories produces endorphins in me,'' he said. ``I love my life.'' As the self-made multimillionaire optometrist/entrepreneur who has pledged $20 million to Florida International University for its proposed medical school, his fast-paced stories reflect a many-faceted man. He has worked his way up from poverty to...