Highlight details that show an important change in the writer's life.

I had entered the world of teenagers, and I wasn't even one of them yet. Lynette Gardner had always been my best friend, until February, when she turned thirteen. I wouldn't be thirteen until August.

—"I'm Not Thirteen Yet,"
Amy Bernstein

What change do the details in the passage help the writer explain?

She was not a teenager yet.
She would soon be thirteen.
She had lost her best friend.
She did not understand how teenagers act.

The details in the passage help the writer explain that she was not a teenager yet, but her best friend Lynette had recently turned thirteen. This is important because it suggests that the writer is experiencing a change in her life as she sees her friend transitioning into teenagerhood and anticipates her own upcoming thirteenth birthday. The details also hint at potential changes in their friendship dynamic and the writer's growing understanding of how teenagers act. Therefore, the change being highlighted is the transition from childhood to adolescence.