Interesting question, and interesting that so many people are giving variations of writer as the response. (Shades of, "If I weren't doing my job, I'd be doing my hobby"? Though that feels an ungenerous reading.) Me? I'd assume some other technical field. If I hadn't got into computers at a young age I can imagine having got into chemistry, say.

The skills I have are those I've developed _as_ a working programmer, less so those that I brought to the job. So this isn't really answering your question. If I'd never become a software engineer, I'd never have developed a programmer's mindset or attitudes.