Are you a scientist because you are paid to do science, or because you were trained to think in a certain way? If you stop doing scientific research (because you’re laid off, or switch fields, or whatever), do you suddenly stop being a scientist?
There is an interesting discussion on this topics on Zuska’s blog, the most recent post is her third on the topic.
I have not worked in a lab (other than supervising Boy Scouts earning their Chemistry merit badge) for 15 years, yet I am still a chemist. I think differently from most people, and analyze everything. It’s partly inborn, and partly learned, but it’s not going to change anytime soon.