Here's my experience with an elderly coder in his mid 50s. He was a decent delphi and .net coder, he was a decent human being, but he had health problems. Most of the week he had hospital appointments. He required nose surgery. His blood levels were low. He needed vitamin d and iron supplements and during our four month acquintance, he never got any better. He constantly forgot things and he feared his lack of iron had caused a permanent damage to his brain. He was a diabetic which gave him license to be more hot headed and harder to persuade. He had accumulated a lot of debts which gave him license to be more hectic and disturbed. Overall, his long life and experience did not outweigh his negative properties.