What made Margaret Atwood a writer?

In biographies there is usually some determining moment in early life that predicts the course of the future artist or scientist or politician. The child must be father to the man, and if he isn’t, the biographer will do some cut-and-paste and stick on a different head, to make it all come out right. We do so wish to believe in a logical universe. But when I look back over he life I led until I began writing, I can find nothing in it that would account for the bizarre direction I took; or nothing that couldn’t be found in the lives of many people who did not become writers.

Margaret Atwood, “A Path Taken, with All the Certainty of Youth” in Writers on Writing Vol. II: More Collected Essays from The New York Times (introduction by Jane Smiley) (New York: Times Books, 2003), p. 11.