It only took 3 years after the invention of the dry-cell battery in 1896 for the first patented flashlights to come out. Since then, they've been a constant companion to police, firefighters, EMS, and other first responders. They've lit the way for mechanics, plumbers, and a whole host of other occupations. Nobody would think of going out into the backcountry without one, either. It's not an exaggeration to say that everyone needs a flashlight sooner or later, so it's best to have one ready when you need it.