I've realized that excel is a language of its own that needs you to understand the jargon and terminology to engage better with it. Every icon on the excel workbook is there for a reason, and it's a matter of perceiving it before you use it.
This course has made me confident and took my little knowledge to an advanced level. Mark explained everything in depth, simply so; even a person using excel for the first time would have a better understanding of it and WHY it is used!