Yes!

This reflects in the fact that great artists are invariably technical virtuosos. Mastery makes way for creativity.

This is due to limited working memory. You may be able to juggle the concepts/math of a particular field in working memory, but that takes away precious space for the combinatorial exploration of novel ideas, or even higher level concepts. Only with practice, when most of the steps in your thought processes can be carried out subconsciously, are you free to do higher-level thinking.

It's not all about working memory of course, since there is subconscious exploration going on as well. Still, things must surface to working memory to be checked that they make sense.

Also, there is also the fact that concepts are built upon concepts. To think at a higher level, you have to truly understand how concepts of the lower level work. It is simply impossible to do it all with limited working memory capacity.