One Month in the School of Affliction will teach thee more than the great Precepts of Aristotle in seven years; for thou canst never judge rightly of human Affairs, unless thou hast first felt the Blows, and found out the Deceits of Fortune.

Thomas Fuller (1654-1734) English physician, preacher, aphorist, writer

Introductio ad Prudentiam, Vol. 2, # 2749 (1727)
    (Source)