My first few stories were duplications of Escape From Jupiter episodes. Later I started borrowing characters and settings and plots from various sources to create something more original. Or perhaps “original” is the wrong word; my first published book was little more than the protagonist from Final Fantasy VIII dropped into the world of Alien and forced to follow the plot of Metal Gear Solid. Yet at the time it was often described as just a rip-off of Maximum Ride.
Perhaps this is how everyone learns. Tara Moss’ childhood writings were mostly Stephen King rip-offs. A great number of popular novels — The Dark Griffin, 50 Shades Of Grey — started out as fan fiction. I assume this is not unique to writers. If one attends a sculpture class, the first assignment is probably to duplicate the Venus de Milo. (Or perhaps a shoebox, or a beach ball. Either way, the students would be copying something.)
Your daily writing challenge is to imitate the style of another writer. Go!