" Perhaps you’ve been in a similar situation: Asked at the last moment to cover for a colleague, you say yes only to realize that you’ve stepped into your worst nightmare. In this case, my colleague had to leave the office on a medical emergency and pleaded with me to cover for a speech he had to deliver the following day. I said yes, only to learn later that the speech was to take place in Sheffield, England (we were in New York), to an audience of educational experts appointed by the then-new British prime minister, Tony Blair. My colleague hadn’t told me what the topic was—something about the Internet—or where his materials (if there were any) were buried. "

― Dan Roam , The Back of the Napkin: Solving Problems and Selling Ideas with Pictures