The Virtue of Selfishness: A New Concept of Egoism
Ayn Rand here sets forth the moral principles of Objectivism, the philosophy that holds human life--the life proper to a rational being--as the standard of moral values and regards altruism as incompatible with man's nature, with the creative requirements of his survival, and with a free society.
"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.