This is a question I’ve often wondered and can really only comment from my own perspective.
As a writer I don’t think I am more critical of average writing, but I do think that perhaps I appreciate great writing more than non-writers might. I think I’m more likely to think “wow, I wish I could write like that” than say, a wig-maker might.
When talking to other writers, I get the feeling that in some circumstances writers may sometimes be even less critical. As someone who works with words all the time, and probably edits their own work, they don’t want to be reading someone else’s work with a mind to editing it. They just want to enjoy it.
Where I think my reading of a book may significantly differ from a non-writer reader is what my mind does with the ideas I read. When I’m reading a novel I will often think I know where it’s going. Sometimes it goes there and sometimes it surprises me. When it surprises me I consider using the concept of where I thought it was going as inspiration for my own writing. Especially if I think that my prediction was better than what eventuated in the novel!
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