The little girl fell face first onto the carpet. For a second, her face reflected uncertainty as she looked around for her father. Sitting on the sofa, he looked at her and smiled. Her uncertainty gave way to giggling as she struggled to her feet.

Just a year and a half old, she fell often, but today she had learned something new. Eyes locked on her father, she took three steps, then threw herself to the ground. This time, the laughter came before she hit the ground. She bounced on the carpet, then looked immediately at him again. He laughed out loud now, reinforcing the day’s lesson. She rose again, clumsy from her laughter, and repeated the sequence again and again with her eyes fixed on his. He held the stare, smiling and laughing along with her. After a while, she staggered to him and jumped into his arms. As she grew tired and snuggled in, he smiled down at her, sad for a moment. There would always be new reasons to laugh, but today’s lesson would never be new again.