Just so you know, Saudi Arabia doesn't teach Philosophy in schools, unlike many nieghbour Muslim countries.
After that, a series of books have increased my knowledge about other religions and my religion too, like Ahmed Deedat books, and Jeffrey Lang's books, and then tons of books which i later have read on various topics like the famous, Origin of Spieces. Many other books have changed many things in me too, and it was on American foriegn policy too, and also about Arabs politics. I also have enjoyed many books which been written about Islam and Muslims, by non-Muslims writers and thinkers, because i enjoy seeing myself and my faith by someone who is not bias, at least toward Islam.