His worst moment in the Grand Daddy of all financial panics in 2008.
Reflecting on the 2008 financial crisis on " Squawk Box ," he said he was most troubled by the "knowledge it was going to fail and the fear and uncertainty associated with that."
But that was only the beginning. "Then the next couple of days ... we had to deal with AIG and talk to Congress," he recounted.
Bernanke has often been called the "right guy, at the right time," because of his extensive study of the Great Depression as well as past financial panics and their effects on the economy.
Facing what he called the "Grand Daddy of all financial panics" in 2008, the former Fed chief said he was concerned the "consequences would be tremendous."
Bernanke appeared on CNBC as part of a promotion tour for his new memoir, "The Courage to Act: A Memoir of a Crisis and Its Aftermath," which went on sale Monday.
On the flipside, he said the best part of being Fed chairman, a job he left last year, was leading the central bank through the turmoil.