What would be a word or short phrase for "someone who learns from their mistakes"?
I thought of insightful, but am not satisfied with it.
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There are various words which describe someone who would be expected to have this among his or her attributes, but not specifically. Clearly, someone who is called astute would hardly deserve the appellation if he or she fails to learn from past mistakes. But the word doesn't specifically mean "learns from mistakes". Various words beat around the bush, some with negative connotations you might not want, like calculating, cunning or shrewd.
Someone whose job it is to learn from mistakes (including those of other people or organizations) and propose actions is a strategist. A strategist must recognize relevant similarities between situations and avoid proposing actions that are likely to repeat failure.
The word has strong connections to war, politics and business. Thus, no everyone who simply learns from his or her mistakes is called a strategist, and if we say something like "he was a strategist in his personal relationships", it sounds like we are describing someone who manipulates people.
It's not an exact fit (an exact fit seems elusive here), but I'd offer the word sensible.
For one, NOAD defines it as:
along with a usage note that adds:
I think the word at least adds a dimension that may be missing from insightful and astute by themselves.