To me, the worst myths about people over 50 is that they look really good, so they must feel really good. Absurd. People over 50 suffer from disabilities and illness that impact their lives significantly, and just because a person can successfully do things one doesn't mean that he/she can do the same thing the next day. I suffer from fibromyalgia and am 59, and frankly am really tired of people saying, but you look so good? You don't look ill to me!
At the same time, though, it's important for us folks over 50 to continue to contribute to the world around us. The myth regarding this is that all we want to do is retire and just sit around fishing or whatever. This is just not true for the majority of us. Most of us would like to keep active, keep learning, and continue to be involved in the world around us. People over 50 make up the largest group of volunteers in the country, and are willing to dedicate their time to help others. So there goes another myth!