Why should I include the context if the audience already knows this information?

The context helps you clarify your thinking while also connecting with your audience

Thinking through the context as you write will help you confirm that you are starting the story at the right point – not making it too broad or too narrow.

Writing it down for the audience will help them work out where you are coming from and what you understand to be the right scope for the story. It will also help your audience ‘enter the world of your story' and leave what they were previously thinking about behind.