Who is Robert from Paris to the Moon and what is their importance?

Robert was a waiter at the Balzar with whom Gopnik spoke at a dinner held in appreciation of the friends of the restaurant after the drama of the waiters' walkout had been resolved. Robert spoke intelligently about another waiter who had lost a daughter and did not know how to cope with his grief. Robert's theory was that the man had not been able to see himself in the abstract, as a victim of circumstances, which would have helped him to cope. Gopnik took this observation as a key insight into the nature of the French people and their penchant for abstraction.