Oooh, great point! I know what you mean! I noticed in the past year or two that I have begun reading books with an entirely different eye than before. In some ways, it detracts from the enjoyment of the book (if the book has too many issues). In other ways though, it helps me, by building up my “reference library” of mistakes to be wary of in my own work. Moreover, I guess, it’s a bit reassuring to realize that a book can have many flaws… and yet still be picked up and distributed by a publisher — and entertain/inspire/help people. Seeing this helps me to be less of a perfectionist about my own writing.
As for punctuation, I feel like I was personally hindered for too long by “proper” punctuation rules, and I’m still trying to break free by mixing it up a bit more. It’s a work in progress. ;)
Thank you for sharing your thoughts, Jim!