I believe that almost every single thing you read has some worthwhile knowledge or wisdom, as well as a slew of material that is wrong or irrelevant or based on values that I don't carry. This includes books, blog posts, and sometimes even short form social media posts.
The key is to read with an open mind BUT don't blindly take everything as gospel. Ask yourself "is this surprising?", or "is this new?" and filter it through the "does this apply to me now?" or "is the person who is saying this worth listening to?".
Throwing out any entire book is shortsighted. Even "bad" books have nuggets of wisdom or new ideas or concepts. Not everything applies to your situation. Some things might apply now. Some things might apply at some point in the future, and having read the book you have an arsenal ready to be deployed when the time comes. Some things will never apply.
If I read a book and have one new original perspective or "aha" moment, it's a net positive.
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