This seems to be fundamental problem with programming texts. I was reading a couple of javascript books recently (eloquent javascript and javascript allonge) and I was struck by the sheer amount of background knowledge you needed to have.
Most of that I've picked up over the last 20 years, but not all of it (or else I wouldn't be reading the books) so I constantly felt like I was having something I knew explained to me in too much detail or having crazy new concepts thrown at me without enough context.
I mostly felt sorry for total newcomers, particularly as I realised most of my knowledge was historical trivia or workarounds rather than actual useful. Once I noticed the above, the amount of crufty irrelevances we have to deal with became obvious, and that's doubly true in JS for the browser.
My only constructive thought was to break things into smaller skippable sections. I personally would skim rather than skip, but advanced warning that the section would only cover stuff I thought I already knew would be helpful.
Mark Pilgrim solved this problem quite well in "Dive Into Python". He presented the working code first, at the beginning of each chapter ("diving in"). If you could read and fully understand the code, then you had no need to read the rest of the chapter. If there were only small things you didn't understand, you could skim to those sections.
This philosophy is stated pretty clearly in the beginning of the book:
You know how other books go on and on about programming fundamentals and finally work up to building a complete, working program? Let's skip all that.
2.1. Diving in
Here is a complete, working Python program.
It probably makes absolutely no sense to you. Don't worry about that, because you're going to dissect it line by line. But read through it first and see what, if anything, you can make of it.
Most of that I've picked up over the last 20 years, but not all of it (or else I wouldn't be reading the books) so I constantly felt like I was having something I knew explained to me in too much detail or having crazy new concepts thrown at me without enough context.
I mostly felt sorry for total newcomers, particularly as I realised most of my knowledge was historical trivia or workarounds rather than actual useful. Once I noticed the above, the amount of crufty irrelevances we have to deal with became obvious, and that's doubly true in JS for the browser.
My only constructive thought was to break things into smaller skippable sections. I personally would skim rather than skip, but advanced warning that the section would only cover stuff I thought I already knew would be helpful.