Ut est rerum omnium magister usus (roughly "experience is the teacher of all things" or more generally "experience is the best teacher") is a quote attributed to Julius Caesar in De Bello Civili, the war commentaries of the Civil War.
[1][2] Since then the phrase has become a common saying regarding learning and leadership.
[3] John C. Maxwell stated that the only way of learning from personal experiences is to reflect on them, something he feels Caesar had done a lot of, which was the only way he was able to become successful and write down his thoughts.
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