Ask HN: What's lacking in Rails education?

I'm a Rails developer with plans to put together a free educational resource. I already have a few ideas in mind, but before I pollute my potential for wide-open feedback, I want to ask:

Has there ever been a point for you where you've found yourself "fed up" because of a lack of tutorials or guidance?

Is there a comparable resource available for a different technology that you feel would address the problems you faced/are facing while learning Rails?