Richard P. Feynman Quotes about Struggle

Richard P. Feynman (2005). “The Pleasure of Finding Things Out: The Best Short Works of Richard P. Feynman”, p.61, Hachette UK
Richard P. Feynman (2011). “"What Do You Care What Other People Think?": Further Adventures of a Curious Character”, p.264, W. W. Norton & Company
Richard P. Feynman (2015). “The Quotable Feynman”, p.112, Princeton University Press
Richard P. Feynman (2015). “The Quotable Feynman”, p.119, Princeton University Press