Is figuring out what is important in a given source of information something you can teach a person?

I'm really good at it how did i become so good at it?
was it cause when a professor presented what was important i could discern the basic characteristics and thus apply to other texts.


What are these characteristics?
Does it depend on the type of text?
Does it depend on the purpose?

The general characteristics seem to be ...
What is the general point the text is trying to get across?
What are the details and definitions of these points that its is trying to across?

However I may be limited to the texts that I have analyzed.