Like how Brian May, lead guitarist for Queen, became an astrophysicist. That’s completely different from what he became famous for, and it makes him unique and interesting to talk about. He isn’t “just another musician” any more.
This is actually the reverse of what happened. Brian May left a career in astrophysics to pursue Queen in 1974, once Queen started getting big. He was about 6 months away from defending his dissertation and earning his PhD. He re-enrolled in his PhD program in 2006, and earned his doctorate in 2007.
Doesn't detract from the author's point, however. Try a lot of stuff. You never know which bet will work out. Just so happened that, for Brian May, being a rock star panned out first!