The people I know that have fallen into this trap tend to have a lot of hubris and arrogance. They probably couldn't even fathom the notion that the label might be applicable. If you're even asking the question, I'd say there's a good chance that you're safe.

More practically: As stated above, if you think you're the most competent person in the room, start looking for other rooms. You don't necessarily have to find new employment to do this—attending meetups and conferences, doing a side project with others, etc. can provide a barometer of where you stand among a wider community.