Something we mentioned today in software engineering is the use of documentation for the three levels of users for your product.
Expert: someone who is very well versed in your product should be able to use it efficiently and quickly. Someone who has a lot of experience with Excel, for example, knows the keyboard shortcut for creating a graph from a selection of text (which is F11 or Alt-F1, depending on what you want to do).
Casual: someone who has used your product before and has some level of proficiency, but does not know the ins and outs. A casual user of Excel would be able to find the button in the interface for creating a graph — certainly slower than F11, but easy to find and deduce should they have forgotten.
Novice: someone who has never or barely touched your product. A novice user of Excel, the sort of person who does not even know that you can create charts out of data (or has never done so before), would need to actively search for the “make a graph” button, which should be intuitive and easy.
People talk about being “pros” with Excel over most other Office products and it’s because Excel is probably the most powerful and the least intuitive, but (But!) its learning curve is clear and satisfying. The more I work with spreadsheets, the more I appreciate shortcuts.