I have been using vim for over 5 years and I only ever use basic cursor movements and character/line replacements. I'm not using multiple windows or buffers or registers or splits. When I want to edit a different file I :wq, navigate to the other file, and vi file. I often find myself in VISUAL mode, not knowing how I got there or what it's for.
I'm sure there are many features that would improve my workflow that I don't even know to look for. Is there a utility or tutorial mode, either within vim or without, that helps competent users become aware of the less-obvious features of vim and when to use them?