In 2007, the rhythmic clatter of a Boston commuter train filled Drew Houston's ears as he settled into his seat, the worn fabric rough against his fingers. The MIT student reached into his backpack, seeking the familiar shape of his USB stick. His hand grasped at empty space where the device should have been, and a wave of frustration washed over him. In that moment, surrounded by the muted conversations of fellow passengers and the soft whir of his laptop coming to life, Houston realized he had left his USB stick on his cluttered desk at home. The train lurched forward, carrying not just Houston, but the seed of an idea that would revolutionize how the world shared information.