You are an expert respected and recognized by your peers. You spell-checked. You reread your manuscript, several times, and found everything clear. Yet the editor rejected your manuscript. The amazon reviewer gave your book a one-star rating. The lecturer covered your essay in red ink. The customers inundated the product helpline with phone calls after reading your user manual. The decision-makers left your document unread, or worse, misunderstood it and were led astray. What they understood was not what you meant. 

These people are readers. But they are not mythical readers: readers with infinite attention, infinite time, infinite memory, and just the right amount of knowledge required to understand your document. They are imperfect readers, a complication, people with limited memory, attention, and knowledge, not people like you. Your knowledge is secured, entrenched in memory. It took you much time and effort to achieve that, years maybe. Readers have hours to rebuild it from your words, maybe minutes. 

The reader’s failure is now your failure. The failing reader is now your accuser, as well as your judge and jury. Chief among the accusations are obscurity, wordiness, sleep-inducement, and time-wasting. Writer, you have to know how readers read, how they succeed and fail, and you can't know that without considering the physiology of reading. You also need skills in Human-Centered product design. After all, you are the designer and *mindnufacturer* of an intellectual product.

The book has 25 "swimming" exercises, some in shallow pools, some in deep pools. Do not skip them. Get your feet wet. One does not learn swimming by watching others swim! It also has countless examples. Evaluate your own writing in the light of what you learn, with the tools we use and recommend. Discover your writing style. Find out what you do that helps or hinders reading. In short, be your own physician. 

Six stories make reading this book more story-like, and the book’s readability score is low enough to be accessible to all, and in particular to non-native English writers. You do not need to read linearly. Start with the chapter that seems more essential: Complex writing? start with the chapter on memory. Dull writing? Start with the chapter on attention. Unclear writing? Start with the chapter on knowledge. Choppy writing? Start with the chapter on expectations. Unconvincing writing? Start with the persuasion chapter. Ineffective visuals? Start with the chapter on visuals. Enjoy them all!