As a single data point, a colleague of mine is a 50+ developer, who was a nurse in the army until a little over a decade ago - and he learned for the sake of a

As a single data point, a colleague of mine is a 50+ developer, who was a nurse in the army until a little over a decade ago - and he learned for the sake of a career change, he didn't move into something that he was already doing on the side, or had done when young.