On understanding....................

      While his mind was neither quick nor facile, young Lincoln possessed singular powers of reasoning and comprehension, unflagging curiosity, and a fierce, almost irresistible, compulsion to understand the meaning of what he heard, read, or was taught.  "When I was a mere child," Lincoln later said, "I used to get irritated when anybody talked to me in a way I could not understand.  I do not think I ever got angry an anything else in my life."  When he "go on the hunt for an idea" he could not sleep until he "caught it," and even then was not able to rest until he had "bounded it north and bounded it south, and bounded it east and bounded it west."

-Doris Kearns Goodwin,  Leadership: In Turbulent Times