“Regret is only necessary as the only way to change us into a better person.”
Related quotes

Webpage Astronauta Marcos Pontes - Entrevistas http://marcospontes.com.br/$SETOR/MCP/OPINIOES/entrevistas.html

“Tell only what is necessary to the person one must tell, and only when it must be told.”
Un Art de Vivre (The Art of Living) (1939), The Art of Leadership

Section 1.2
Workers Councils (1947)
“What is necessary to change a person is to change his awareness of himself.”
As quoted in Life In the Open Sea (1972) by William M. Stephens, p. 21.
1970s and later

Comment of late 1788 or early 1789 upon his slaves http://www.mountvernon.org/george-washington/slavery/the-only-unavoidable-subject-of-regret/, as recorded by David Humphreys, in his notebooks on his conversations with Washington, now in the Rosenbach Library in Philadelphia<!-- as quoted in "Housing and Family Life of the Mount Vernon Negro," unpublished paper by Charles C. Wall, prepared for the Mount Vernon Ladies' Association (May 1962), prefatory note]. -->
1780s
Context: The unfortunate condition of the persons, whose labour in part I employed, has been the only unavoidable subject of regret. To make the Adults among them as easy & as comfortable in their circumstances as their actual state of ignorance & improvidence would admit; & to lay a foundation to prepare the rising generation for a destiny different from that in which they were born; afforded some satisfaction to my mind, & could not I hoped be displeasing to the justice of the Creator.

Letter (4 February 1916), quoted in F. L. Carsten, The Reichswehr and Politics 1918 to 1933 (Oxford: Clarendon Press, 1966), p. 105.

“Sometimes there's not a better way. Sometimes there's only the hard way.”
Source: The Fox Inheritance