Designers and craftspeople have long understood what theorists are only now proving: we think through our fingertips. In design thinking, physical practices like sketching, prototyping, and handling materials are not just ways to show ideas; they are ways to discover them. This physical engagement taps into tacit knowledge—the deep, sensory-motor understanding of how things work that we cannot easily put into words. By physically manipulating materials, we let our bodies lead us to unexpected, innovative solutions.