Found this enlightening:
Impostor syndrome is the frequent feeling of not deserving one’s success, and of being of a failure despite a sustained record of achievements. Highly successful people often experience it throughout their careers, especially when they are members of a group that is underrepresented in their profession.
As a dean at UBC and Princeton and as president at HMC, I have started each academic year by telling the first-year students about impostor syndrome, since I know many of them will have times when they wonder whether they belong and whether they are as talented as the other students around them. I also give them advice on how to cope with impostoritis: Ask for help and take it, recognize that such feelings are common and are often connected to high degrees of success, surround yourself with people who encourage you, share your feelings with others, celebrate your successes, be willing to try new approaches if your usual one isn’t working, and don’t let your fears stop you from giving your best effort.