My blow dryer brush is one of my most prized possessions. When I started using one to transform my limp, wavy hair into pert, bouncy curls, I was so flushed with compliments that I barely knew how to act. Suddenly, I was that girl — the one people asked, “Wait, how did you get your hair so perfect?”So the day that my blow dryer brush, a Shark FlexStyle Air Styling & Drying System, refused to start and an indicator light blinked red, I went through the five stages of grief in rapid succession.