Definitely don't let this discourage you. I've only been using vim for about six months and I do not know all the commands and modal changes on this diagram.
The great thing about vim is you do not need to know very much to be productive, but every day you learn something new that will make you more productive.
While this is a great reference writing a vim plugin or looking up the behaviour of a specific command, I don't really see it as a learning tool.
Au contraire, I find this to be a great learning tool. As a post-novice vimmer, this is the first time that I've been able to see it all laid out like this so that I can see what I know already, what's left to learn and how it all fits together. I didn't even know "select mode" existed before this (though I promise I'll never use it – even MacVim uses visual mode with the mouse). I've saved this to my help/vim folder and I plan to refer to it periodically.
I agree, it's not really a learning tool (for a novice). Some commands here are pretty obscure; you wouldn't use some of them very much or at all, but that's not evident in the diagram. And you also have the right idea about learning vim incrementally (http://yehudakatz.com/2010/07/29/everyone-who-tried-to-convi...), instead of the "learn everything in parallel" approach that some advise.
Thanks for the link. I'm only just starting my second year of University now and I feel like skills with Vim will be an invaluable thing to have for my course.
The great thing about vim is you do not need to know very much to be productive, but every day you learn something new that will make you more productive.
While this is a great reference writing a vim plugin or looking up the behaviour of a specific command, I don't really see it as a learning tool.