Dictionary.com
Thesaurus.com

school of hard knocks

American  

noun

  1. the experience gained from living, especially from disappointment and hard work, regarded as a means of education.

    The only school he ever attended was the school of hard knocks.
school of hard knocks Idioms  

  1. The practical experience of life, including hardship and disappointments. For example, A self-made man, he never went to college but came up through the school of hard knocks. This idiom uses knock, “a blow,” as a metaphor for a setback. [Mid-1800s]

Etymology

Origin of school of hard knocks

An Americanism dating back to 1910–15

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.