as a training... i read. That is all. I begun when i was 5. Never stopped. So i nearly always was like that. The more you read the more you train your brain to read. And your mind to understand how to deal with knowledge and information. Filter it, classify it, absorb it, apply it.
For non fiction, yes it happens. Lot of book sjust repeat the same thing over and over again. When you begin to read a chapter and can complete what will be said in the next 20 pages just from your understanding of the whole situation, reading it is a loss of time. And it would make me be bored and get down from "The Zone".
I keep track in my brain. I have the advantage of being able to always remember if i have read something by just looking at the backcover and the first lines. I still have to forget a book i read. I can not remmeber all the technicalities of course but far enough to know if i read it before or not.
I reread the books i really like or need when needed anyway. Mainly during vacations.
I'm not keen on skipping chapters! Do you do the same with non-fiction?
Another question - how do you keep track of what you've read? (would be happy to hear from others esp. Alan on the same topic)