Synthesized answer
The provided passages do not contain information about what questions remain unanswered in Stephen Hawking's life or work. The passages describe "My Brief History" as a book where Stephen Hawking tells the story of his life in his own words, expanded from a lecture [Passage 1]. It also mentions his previous bestselling book, "A Brief History of Time" [Passage 1].
Therefore, the passages do not provide an answer to the question of what questions remain unanswered.
Synthesized from the book passages below. Chat with the book on Feynman for follow-up.
From the book
Title: My Brief History by Stephen Hawking Description: Stephen Hawking is one of the most brilliant cosmologists of our time, and author of the 10 million copy bestselling A Brief History of Time, one of the iconic books of its generation. Now, for the first time, he tells the story of his life in his own words, in a book expanded from a lecture of the same name.