Former Westpac boss David Morgan says company chief executives are "ridiculously overpaid" but the intense pressure of the job causes some to "literally weep" in private.

A new biography of the former bank chief and senior Treasury official details how he took to mentoring executives after his time leading the bank, in part because life as a CEO was "seldom openly discussed".

Former prime minister Paul Keating with former Westpac CEO David Morgan at the launch of the latter's biography in Sydney. Credit:Dominic Lorrimer

"Most people don't talk about it honestly," Dr Morgan said in an interview with the book's author, journalist Oliver Brown.

"Yes, CEO life is very glamorous. You're recognised, you're given the best seats in restaurants, and you're ridiculously overpaid. But you need stamina. As the leader, you rarely play the grand final, but more an endless succession of semi-finals," Dr Morgan said.