Life is filled with contrasts for Cavalin, a 17-year-old from San Gabriel, California, who has dashed by major milestones as his age seems to lag behind. He graduated from community college at age 11. Four years later, he had a bachelor's degree in math from the University of California, Los Angeles.
From what I understand, here "dashed by" means he quickly get lots of milestones. But why does it say "seems to lag behind" at the end of the sentence? Is the author trying to say that even though he got so many achievements he's still wasting his genius?