The problem will be solved in a practical way. Don't look for complex answers.
It's perfectly okay to tell people that you don't know. We all, at times, must admit that we don't know everything. People who are perfectionists don't like to admit when they don't know something, or when they are wrong. However, if you can never admit that you're wrong, or you can't tell people that you don't have all the answers, how can you expect to learn and grow and gain their respect?
Recruiters get paid to place great people in great jobs. If you don't sell yourself well to the recruiter and show them just how amazing you are and how serious you are about finding a great job, then you aren't going to dazzle them.