Quick, what's XIV squared?
You can't do advanced math without the zero. And you can't write precise prose without a well-developed vocabulary.
The magic of the alphabet is that twenty-six letters are all you need to spell every word. The beauty of Lego blocks is that you don't need very many to build something extraordinary.
Imagine how hard it would be to get anything done, though, if you only knew 17 letters.
In most fields your work is hindered if you only have a few of the most basic tools. Understanding more of the building blocks of finance, or marketing or technology are essential if you want to get something important done.
Here's my advice: Every time you hear an expert use a word or concept you don't understand, stop her and ask to be taught. Every time. After just a few interactions, you'll have a huge advantage over those who didn't ask.