"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 (the full list is here):
Provides unique coverage of Intel's Pentium chip. Explores hardware programming aspects that affect code performance. Features innovative optimization techniques not found in any other book. Includes the useful Zen timer-a hands-on software tool for measuring code performance. Presents creative "right-brain" Zen approaches to the art of writing PC