Writing a book is a great thing to do and gives people a glow of satisfaction, having committed their thoughts to the record. Authors should rightly feel a great sense of achievement about this worthwhile endeavour. However, some writers are overtaken by the thought, “I’m writing a book!” and so get carried away and try to cram too much into their work, thereby clouding its focus.
It’s the trap of producing a “Magnum Opus on Life The Universe and Everything” (a la The Hitchhikers Guide To The Galaxy). This is where the author throws in every bit of knowledge or wisdom they have gleaned, or quotable quote they’ve stored up over the years – whether it’s relevant to the topic at hand or not.
It’s very easy to go off at a tangent when writing. It’s also hugely tempting to throw in other nuggets of information that may, in themselves, be interesting, but don’t add anything to the point you’re making.
Resist the urge, stick to your writing plan and keep focused! A good commissioning editor will spot immediately if you are wandering off topic frequently and is likely to dismiss your book as unfocussed or badly written.