"What is the book that changed your life? (not novels or religious texts)"
I think it's a wonderful way to connect in a less superficial way and learn a little more about each other. It's also a wonderful way to discover new books worth reading.
This is one of them:
Atomic Habits: Tiny Changes, Remarkable Results
A supremely practical and useful book James Clear distils the most fundamental information about habit formation, so you can accomplish more by focusing on less - Mark Manson, author of The Subtle Art of Not Giving a F*ck.