'Imposter syndrome' is a curious contemporary phenomenon. It describes that strange feeling of the inadequacy of one's professional expertise and knowledge, and therefore the fear of being exposed as a "fraud". The IT industry is famous for the many real imposters in its ranks, the people who reinvent themselves as IT experts, but I also believe that most of the minority of people who really understand the business and their role within it suffer from imposter syndrome. I sometimes wonder whether IT people are so inclined to subside into management roles purely because they either think themselves to be imposters, through the stress of 'burnout', or because they really are imposters.
This loss of confidence in one's own expertise is an occupational hazard. In areas of knowledge such as science, it is easy, when faced with the feeling that you are a fraud, to retreat into an arcane specialization such as the nesting behaviour of ivy bees, or the surface chemistry of III-V semiconductors. Who can argue that you're not an expert then?
The problem for developers, and particularly database people, is that most of us are forced to be generalists, rather than specialists. In a large organization, perhaps, we can avoid those creeping feelings of being an imposter by being a specialist, finding a cosy role doing nothing but modelling data or dealing with data-exchange systems. Database administrators or developers rarely get the chance because their role requires a diverse and changing range of skills and knowledge, and when they change jobs, they discover to their dismay that there many others, entirely different, elsewhere.
How then can one combat imposter syndrome? I believe that the best way to survive as a technical expert, with a broad knowledge, is to adopt the strategies of the successful lawyer. To handle highly technical cases, they need to argue eye-to-eye with people who are genuine technical experts in their field, and on esoteric topics such as the chronic symptoms of organo-phosphorous poisoning. Their skill is in the rapid assimilation of knowledge and detail, by knowing where to look for it. Then, once the case is over and the file is closed, they manage to forget it all. Effective preparation is everything. Like most people, I'm good at the 'forgetting' side of this technique, but struggle more with the assimilation side.
Actually, this sort of skill can be learned and there are many established techniques for doing so. It requires no mutant mental powers. Many of my colleagues in IT have an extraordinary facility for it. When asked in an interview if they had any knowledge of a particular arcane facet of relational databases, I remember a candidate saying, "None at all, but in a couple of days I'll be an expert." That wasn't arrogance, it was explaining that to be effective in an IT team, it is necessary to constantly learn and forget skills. It is not the existing knowledge, but the skill of acquiring it rapidly that's important.