Was there any book that converted you from spaghetti coder to a good programmer?

Spaghetti programming = writing code without any structure or thought and ending up with a mess that you can't yourself debug or maintain after a few months.

Good program is something that is elegant, easy to maintain, easy to read and understand, etc.

Is there any book that you read in your journey as a programmer (professional or otherwise) that just warped your thinking model and made you a better programmer overall?

Or maybe a side project that you did that created this paradigm shift?