Recommend me a fantasy book that changed the way you think or live.

I'm looking for a fantasy book that challenges the way I think or see the world. I want something that has depth, that offers more than just a good story, something that left a lasting impact on you, whether it changed your beliefs, or even inspired you to live differently. It could be anything from high fantasy to urban fantasy, or sf. What fantasy book made you think deeper or changed how you approach the world? I'm excited to hear your recommendations!