I've always thought that software is a young man's game, whereas law is an old man's game.

This is because when new legislation is introduced, the first thing that any discussion of it does is to consider what the law was 200 years ago. New laws are mostly tweaks on existing laws (including case law), and will be interpreted as such by the courts. Even entirely new laws are interpreted in terms of existing laws. Of course, there are some new laws and new cases to keep up to date with.

But compare this with programming, where most successful practitioners didn't have or need any idea of previous languages or approaches. Which is probably one of the reasons that software is reinvented every decade or so. Law is not.