Anyone who answers "yes" to this needs to read (or re-read) How To Get Rich by Felix Dennis*.
He specifically talks about the dangers of associating too closely with a certain industry - he made the same mistake by thinking he was a "publisher", just because his first business was Dennis Publishing. He then started Microwarehouse and made a shitload more cash as well.
The tl;dr version is that you're an entrepreneur who looks for opportunities. Just because Internet marketing is the best one you've found so far, doesn't mean you're an Internet marketer.
Personally - I'm using this to teach me the discipline of marketing, because if I master that, I can use it to build any business.
*Yes, I know that's the 15th time I've talked about this book. It's the only "make money" book I've seen that isn't a bunch of guru bullshit from someone who's only ever made money telling people to make money.