Thoughts On Outside Influences

So, I am reading The Zombie Survival Guide, and I am loving it. It is a tremendous book, thoroughly planned and executed. As I was reading it today, I started to think about the concept of a very realistic field guide based on a fictional subject. What if I wrote field guides for some of my own larger fantasy worlds?

And there was the inspiration. If I could make a field guide for my large-scale worlds, played totally straight, it would both give me excellent understanding of the finer points as well as give me ways to implement it in stories themselves (which, it occurs to me now, happens with World War Z).

I probably could have come up with this idea at some point. However, this idea came sooner because I was reading somebody else's book.

When I was younger, I really opposed the idea of gaining ideas or inspirations from reading people's stories. I felt like it was either cheating or stealing. Nowadays, I realize that theft is not in the idea but the execution. Writing a field guide isn't theft. Writing a zombie survival guide would be.

Outside influences can speed up the creative process. If I never read The Zombie Survival Guide, I could have come up with a fictional field guide idea on my own and never thought of myself as a thief. So why should I feel bad if reading somebody else's field guide made me think about doing one of my own faster?