What book(s) has changed your life?

What clicked and made you have a different mindset? How long did it take to start changing and how long was the transformation? Did it last or is it an ongoing back and forth between your old self? I want to know your transformation and success.

Any kind of change, big or small. Anything from weight loss, world view, personality shift, major life change, single change like stopped smoking or drinking soda to starting exercising or going back to school. I want to hear how people's life were a bit or a lot better through reading and your progress.

TIA 🙏