* * * Ben Affleck was born in Oakland but raised with his younger brother, Casey, as everyone knows, in Boston — Cambridge, specifically — by his mother, a grade school teacher, and, until he was about 10, his father, a onetime theater writer-director who later worked as a janitor and bartender. (Affleck says his father was "mostly unemployed and an alcoholic," sometimes "living on the streets.") When Affleck was 7, a casting director friend of his mother invited him to audition for a local PBS children's series, which he landed and "really liked." A year later, Matt Damon, a fellow aspiring actor two years his senior, moved into a house two blocks away — their bedrooms were visible from one another's — and they became fast friends. Affleck introduced Damon to his agent, who also signed Damon, and the youngsters began traveling together to Boston and New York for auditions. (Both were extras in 1989's