I strongly relate to your analysis, as I have often found myself overwhelmed due to a lack of working memory capacity, which has often resulted in failing a whiteboard interview, or being unable to provide a short answer to a question that I have never thought about before.

I am more comfortable with deep thinking, or reflection, which allows me to come up with more complex analysis, while this process translates quite well when I have homework challenges.

I used to test some of my mental capacity with pseudo-IQ tests and realized that the factor that would penalize me the most was lack of time.