Make the most of your regrets; never smother your sorrow, but tend and cherish it till it come to have a separate and integral interest. To regret deeply is to live afresh.
Source: Journals, 1906, entry for 13 Nov 1839.
-- Henry David Thoreau, (Jul 12 1817-1862), US essayist, poet, naturalist; He is best known for his description of life at Walden Pond, Walden, 1854 and his essay Civil Disobedience, 1849.