I got it when I was 30 years old and you know what? I use the programming skills I have now plus the knowledge aquired in my previous job. The result is a programmer who also is a specialist in X or a X specialist who can develop software in this field.
Super +1 for that, the dual-field advantage can easily compensate the belated entry into a new market. For an easy example, if your current career is in anything related to finance / banking, there's a ton of jobs for developers who also have deep understanding of this business. Indeed, you can find yourself in advantage over younger, better-trained hackers whose single expertise is with programming.
I got it when I was 30 years old and you know what? I use the programming skills I have now plus the knowledge aquired in my previous job. The result is a programmer who also is a specialist in X or a X specialist who can develop software in this field.