What is the “misadventure” that William Douglas speaks about?

Douglas refers to the incident at the Y.M.C.A. swimming pool where he almost drowned as a “misadventure.” The author was about ten or eleven years old at the time and had barely begun to learn swimming, primarily by aping others. As he was thrown suddenly into the water by someone and he couldn’t swim, he started drowning. The struggle to come to surface and to avoid getting drowned left him with a deep fear of water which deprived him from enjoying water-related activities for many years.