The Guardian’s Oliver Burkeman explains Arno Minkkinen’s theory of success in creativity:

There are two dozen platforms, Minkkinen explains, from each of which several different bus lines depart. Thereafter, for a kilometre or more, all the lines leaving from any one platform take the same route out of the city, making identical stops. “Each bus stop represents one year in the life of a photographer,” Minkkinen says. You pick a career direction – maybe you focus on making platinum prints of nudes – and set off. Three stops later, you’ve got a nascent body of work. “You take those three years of work on the nude to [a gallery], and the curator asks if you are familiar with the nudes of Irving Penn.” Penn’s bus, it turns out, was on the same route. Annoyed to have been following someone else’s path, “you hop off the bus, grab a cab… and head straight back to the bus station, looking for another platform”. Three years later, something similar happens. “This goes on all your creative life: always showing new work, always being compared to others.” What’s the answer? “It’s simple. Stay on the bus. Stay on the fucking bus.”

A little way farther on, the way Minkkinen tells it, Helsinki’s bus routes diverge, plunging off on idiosyncratic journeys to very different destinations. That’s when the photographer finds a unique “vision”, or – if you’d rather skip the mystificatory art talk – the satisfying sense that he or she is doing their own thing.

Full Story: The Guardian: Helsinki Bus Station Theory

Really it’s just a metaphor for persistence being the key to finding your own voice. It’s not a perfect metaphor. As some on Metafilter have pointed out, some people probably should get off the bus and try something different. Grant Morrison got off the music bus, for the most part, and got back on the comics bus. That seems to have worked out pretty well. Gary Numan wanted to write sci-fi stories, but he ended up as a great musician instead. Many fine writers originally wanted to be painters. But it’s not bad as far as metaphors go.

See also: Ira Glass’ advice for beginners: creative people have good taste, and when you start out you’ll be bad and you’ll know it. That makes many people quit before they get good.