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)