A red ball rolls across the floor. It’s smooth and hard under my fingers. I push it with my hand, watching as it bounces lightly over the carpet. Each bounce sends a tiny crackle through the fabric. A blue wall looms nearby, its corners sharp against the white ceiling. The ball glides to the edge of a toy box, then tumbles off into a pile of blocks. I kick it gently back towards me. It skids across the wood until it comes to rest in front of my feet. My toes tap at it softly, and the ball wobbles before rolling once more, this time toward the door.