Learned something very important from an unrelated book

Have you ever learned something important from reading an unrelated book?

For example, this just happened to me today. I was reading The Long Way to a Small Angry Planet, and Dr Chef advises Rosemary to never consume caffeine on an empty stomach. I googled if that was true and discovered the reason for all of my health problems for the last few months. I guess that’s the importance of reading. Lol