I started flying on my 13th birthday. I had the good sense to stop flying as pilot-in-command at age 64 after a career in the US Air Force and as an instructor pilot. Why? I saw excellent pilots in my age killing themselves and others in air shows and on routine flights due to their deteriorated physical and mental abilities. It doesn't take a rocket scientist to figure out, as a Clint Eastwood character said, "A man [or woman] has to know his [her] limitations."