Writing and the Audience

Ever since I have been writing short stories and essay's I have always written it as if the reader knows exactly what I am thinking. I know that is one of the number one rules of what not to do in writing. When I start my essays I always think about the reader and how they are ignorant of what I am saying, but then I seem to trail off into my own little world, and I get a bit carried away. Then when I proof read my essays and I say to myself "What was I thinking?!" Hopefully I will get out of this habit soon, with the help of my peers in class and help from Heather.