The film that I've posted so often about is perfect example of how inspiration comes from sources outside one's own industry.
As a reference, my background - I did graphic communication at uni. Then I worked for two years as a graphic designer. Now I'm applying for advertising jobs.
I've also been massively inspired by this (yes this) post.
I love the idea that you advertise what you're best at through the method that you're worst at (or related to but not experienced at).