I used to scoff at the idea of chemtrails, until I remembered something. More than thirty years ago, I watched a plane cross the sky leaving a 'contrail' behind it. I was on a swingset, and kept an eye on that 'contrail' as it turned into a long cloud that lingered in the sky. Later, my dad came out and I told him I was watching the cloud that an airplane had made. He tried explaining to me how it was impossible for me to have seen what I saw, because planes didn't make clouds like what was now hanging across the sky.