<p>I found the selected answer exceedingly unfair.</p>
<p>The only possible audience for this self answered q/a is someone who is still learning about the topic at hand. They are struggling to ask a question for learning resources and it's very likely because they are early on the journey  to deeper knowledge and require guidance on how best to make it.</p>
<p>For them, I'd like to say that the simple reality is - you won't know what you don't know.  But that's ok, instead of worrying about what you need to learn, think more deeply about what you want to do with what you learn.   What are your goals?  How will you utilize what you want to know?</p>
<p>Try to be as short term and specific as possible, though some longer time frame context can help.</p>
<p>If you don't wish to answer that question (some don't), then the answer above will be your only alternative.</p>
