One thanksgiving I showed an 80 year old how to put a candle out with a hand gesture. He was really into it an in his words there are far fewer really new things at 80 than you might think. Which struck me as the core of a lot of ageism, when your young doing just about anything is a solid learning environment, but eventually it becomes tough to continue to develop new skills. Your job becomes all about leveraging what you already know not expanding you into new areas the same for your social circle and if your not careful hobby's.