A Sharp­Brains read­er just for­ward­ed this very thought­ful let­ter by invest­ing leg­end Byron Wien, as a liv­ing exam­ple of many prin­ci­ples espoused by our new book. The let­ter fea­tures twen­ty excel­lent life lessons learned, includ­ing the five below. Enjoy! (bold empha­sis mine) Byron Wien Dis­cuss­es Lessons Learned in His First 80 Years: “1. Con­cen­trate on find­ing…