Every utterance that makes a difference changes the situation which called it forth, and thus changes its own context. The letter will mean something different to latter-day readers.
… in the sphere of culture the more unexpected something is, the stronger will be its influence on the cultural situation after it has come into being. An event that is quite unexpected (the appearance of an unpredicted text) radically alters the situation of the next one. The improbable text becomes a reality and subsequent development makes the fact of its existence a starting point.
— Yuri Lotman (1990, 235)