He was solving math problems at 14 months, reading and correcting adults' grammar by 2 - the same age he decided to become a vegetarian. He was explaining photosynthesis to kindergarten classmates at 5. He breezed through 10 grades of school in three years, graduated with honors from high school at 9, founded an international youth advocacy organization, met with prime ministers and presidents, and was nominated for the Nobel Peace Prize. Twice. Now, 13-year-old Gregory Robert Smith is about to add another line to his resume: College graduate. Greg will receive his bachelor's degree in mathematics May 31 from...