My opinion after programming for 55 years: The field repeatedly expands beyond what your can mentally encompass. This is not because of cognitive decline. Tr

My opinion after programming for 55 years: The field repeatedly expands beyond what your can mentally encompass. This is not because of cognitive decline. Trying to separate the effects of these two factors seems impossible. Two things are certain: you will have to repeatedly restrict your scope; and your productivity will continue to expand beyond what you thought would ever be possible. You do have to keep active in the field to avoid losing your edge though.