A person at the top of their field takes a job and settles into a routine. Time passes, and they have not kept up with the changes. In media and technology, this is a huge concern. Before they know it, they don’t really qualify as an expert in their field anymore.
While I am more of a generalist than a specialist, there are some areas that I used to know a lot about. I say used to because I chose not to stay up on the current trends in those areas. My passions and job requirements took me in a different direction. For example, I used to know quite a lot about audio recording. This was back in the days of 2 inch, 24 track analog tape. Within a couple of years after I left the recording studio digital tape, and then hard disk recording was taking off. A few years later I returned to the same studio to find most of the gear I knew had been replaced. I was no longer an expert in multitrack recording. It would be a mistake for me to try to act like I am.
How do you keep your expert from losing the edge?
Hopefully the person is a life-long learner, with a desire and passion for the area they serve in. Encourage them to read, attend conferences and conventions, and take part in discussions with fellow experts. If they need to be re-certified, help them do it. Encourage them to stay up on any new technology or techniques in their field.