Editor’s note: Mary Frances Ruskell is a senior at Heathwood Hall Episcopal School in Columbia, South Carolina. CNN  —  I spent my freshman year of high school despairing that I hadn’t invented a synthetic human heart, launched a tech start-up, written an opera or raised $10 million for charity. I ran track, sang in a cathedral choir and taught little kids how to kayak in the school’s outdoor club. I was plenty busy. Where in the world had I gotten the idea that I was supposed to be doing those