Contrails

When I was younger, I thought all clouds were created from jet contrails. On clear, sunny days I would look up to see these thin, white lines being painted on the sky. At first they seemed fragile, bound to break apart, but as time ticked on they got bigger, and wider, and floated for hours. In my mind, pilots got paid to be aerial artists and the sky was their canvas, clouds their art. How could I think they were anything else?