I fully agree. vimtutor is just about the best introduction to vim out there.
After mastering it, I recommend hanging out on #vim on freenode. You'll get a great education just from reading the questions/answers others have. And any time you find yourself doing something complex in vim multiple times, ask about it on #vim and you'll probably get some suggestions on how to do it more efficiently.
Another thing that helps is reading the documentation for every option you put in your ~/.vimrc, and trying to fully understand what's happening there and why. And try to avoid blindly using other people's .vimrc's. Instead, use their .vimrc's for inspiration, transferring over only those parts you understand and find useful.
A thousand times yes to this, and not just because it's how I learned. It puts the commands into your muscle memory. You should not be trying to memorise anything; just follow the directions and don't move on until you complete each step. Then when you're done, do it again. Do vimtutor as many times as you need to until you really don't need to think about how to manipulate text.
And yes to the ~/.vimrc advice here. You should start with an empty dotfile and build up from there. DO NOT make the mistake of starting out by installing Janus. There shouldn't be anything in your ~/.vimrc until you understand what it does, and editing that file should be done incrementally by the user instead of being a copied file. This is part of the learning process.
After mastering it, I recommend hanging out on #vim on freenode. You'll get a great education just from reading the questions/answers others have. And any time you find yourself doing something complex in vim multiple times, ask about it on #vim and you'll probably get some suggestions on how to do it more efficiently.
Another thing that helps is reading the documentation for every option you put in your ~/.vimrc, and trying to fully understand what's happening there and why. And try to avoid blindly using other people's .vimrc's. Instead, use their .vimrc's for inspiration, transferring over only those parts you understand and find useful.