Maturity means understanding, as much as possible, the different characters and modules that are active inside your own head. The mature person is like a river guide who goes over rapids and says, “Yes, I have been over these spots before.”
David Brooks (b. 1961) Canadian-American political and cultural commentator, writer
The Social Animal, ch. 18 “Morality” (2011)
(Source)
Often paraphrased: "Maturity means understanding the different characters inside our own heads."
