David and I met in a sandbox when we were five. I was trying to build a castle, but the sand was too dry and it kept collapsing. I was on the verge of tears when a boy with bright, dark eyes and a confident smile walked over.
 "You' re doing it wrong,"  he said, not unkindly. He grabbed my little plastic bucket, ran to the water fountain, and came back with wet sand.  "You have to use wet sand. It sticks together." 
He helped me build the most magnificent castle our kindergarten playground had ever seen. From that day on, I was his shadow.
  He was a year older, and he carried that one year of seniority like a badge of honor. He was David, and I was his Sarah. He protected me from playground bullies, shared his snacks with me, and taught me how to climb the monkey bars.
My mom used to laugh about it.  "Sarah, are you going over to the Chens'  again? You' re going to wear a path in the grass between our houses." 
David' s mom, Mrs. Chen, adored me.  "Oh, let her come! David is so much calmer when Sarah is around. It' s the only time he isn' t getting into some kind of trouble." 
I' d sit on the floor of his room, watching him assemble intricate Lego models, handing him the pieces he asked for. He was always building things, creating worlds. It was contagious. I started drawing, sketching the things he built, then imagining my own.
His parents were wealthy and a bit distant, always busy with their work. They provided him with everything he could ever want, but not a lot of direct supervision. My family was middle-class, warm and ever-present. He seemed to like the chaos and affection of my house, just as I was drawn to the quiet, structured order of his.
One afternoon, his mom' s friend came over with her own daughter, a girl with frilly pink ribbons in her hair. The girl tried to join our Lego session.
David put a protective arm in front of his creation.  "No. I don' t like playing with other girls." 
The woman laughed.  "What about Sarah? She' s a girl." 
David looked at me, then back at the woman, with the dead-serious logic of a six-year-old.  "Sarah' s not a girl. She' s Sarah." 
For him, I was in a category all my own. I wasn' t just some girl; I was his person. That feeling, of being chosen, of being special, became the foundation of my world.
My childhood was a sun-drenched, carefree time. I was loved, a little spoiled, and completely naive. My biggest problem was what to wear to school or whether I' d finished my homework. Life was simple. And at the center of that simple, happy life was David.
I never learned to stand on my own two feet because I was always happily walking in his footsteps. I never imagined a future that didn' t have him in it. Why would I? He was my best friend, my protector, my world.
I had no idea that the very thing that made me feel so safe was the beginning of a cage I was helping to build around myself.