Hard to say. A large part was that I identified so much with one of the main characters, Larry. Not so much in his appearance, personality, or relationships with people (though one relationship he had in particular I saw as very similar to one of mine), but more in his character, his interests, his motivations, and his mannerisms. I saw a lot of myself in that (and I make that evaluation without considering it either inherently good or bad), so a lot of his experiences and choices in the book resonated with me, and made me consider my own. Additionally, the manner in which much that happened in the book was regarded by the author (who is, incidentally, the narrator), I found very appealing, and agreed with it to a substantial degree. It wasnt even that this led to an outright challenge to my previously held beliefs, just that they offered such a fresh new way of looking at things (from my perspective anyway), that I was struck with how simple and reasonable these opposing ideas seemed.
