I work in pensions, and I'm fully invested in the the need to save for the future competing against changing demographic and social change, as both can easily be seen in the fabric of every day society. However, my role within this industry is marketing and PR and so the interest extends outside of saving. I look at the behavioral direction of advertising, whether pension related or not, and the articulation and delivery of media spokespeople, especially politicians.
Both the subject matters and the disciplines of the functions interest me enormously, and I see neither as a burden. I'll take interest in a politician talking about benefits and retirement as much as I enjoy looking at a TV advert for cosmetics or any subject, looking at how they aim to engage with the target audience.
I think part of it is how much you enjoy your job and your profession within it, and part how much you invest / believe in your subject matter. It is a special skill if you're able to be a high achiever in one or the other or both and still be able to segregate them from your other activities.