If you’d asked me to chart my family on a graph, the data would’ve told the story long before I admitted it out loud. My line sloped steadily—do the work, pass the class, fix the store’s POS when it froze at Christmas. My sister Emily’s line looked like fireworks: glittery bursts, loud exits, sudden dips. My parents tracked only the sparkles. I didn’t set out to keep score. But numbers have a way of keeping themselves. Modest eighth-birthday cake; two months later, Emily’s backyard carnival comp