The awareness of the ambiguity of one's highest achievements (as well as one's deepest failures) is a definite symptom of maturity.
Source: In The Speaker's Electronic Reference Collection, AApex Software, 1994.
-- Paul Tillich, (Aug 20 1886-1965), German-US theologian; He was a leading Protestant thinker who brought Christianity and contemporary culture together, e.g., I Loved a Girl.