Existence is play. Communication is play. You throw a ball of
words "out here". I caught the ball (read your words) and I'm
throwing it back to you (responding). To me, you exist, because
the ball came from someplace and arrived into my eyes. I threw
the ball at somewhere. I can't guarantee that I will be
understood (that anybody will catch the ball) but I knew someone
threw it at me, and I threw it back. Therefore, to me, you exist
as the thrower of the ball.