In order to better understand the relationship between losing something, getting lost, and gaining familiarity as a result of such loss, an exercise in psychogeography was undertaken. 100 letters written by myself and address to a stranger were made. Each letter was enclosed with a stamp and sealed. On the back it's written: "This is not a lost letter: open me, read me". The 100 letters were "accidentally lost" around the city of London in public and private places. The letter asked whoever reads the letter to get in touch by responding by mail or email to the writer. The letter asked for a story, a secret, or an object related to London. Out of a 100 letters "lost", a single response was received. The experiment was documented in a book titled "This is not a lost letter".