It is an impossible calculation.

They would be exceptional no matter where they grew up. How many people in any community are named MacArthur geniuses or make films that get Oscar whispers? Yes, their success is owed to hard work, intelligence, sheer will. But there are a lot of smart, hard-working people in places like Liberty City. That is seldom enough.

So much depends on luck and timing. On not making the irreversible mistake. On meeting the right person at the right time who pushes in the right direction.

For Mr. Jenkins, one person who pushed was Pamela Gilzow Rodriguez — at the time a young, blond third-grade teacher who sped through Liberty City each day in a beige Corvette. She recognized his talent as a writer and was the first teacher to give him an A. (She keeps a file, still, of his essays from third grade and the letters he continued to write her as an adult.) There was also luck: He saw a poster for a filmmaking class as a student at Florida State University, and he thought that might be fun.

For Mr. McCraney, a turning point came when a high school counselor, worried about the bullied young man who didn’t seem to fit in anywhere, referred him to Teo Castellanos, a renowned playwright who ran a theater program for marginalized communities. He would become Mr. McCraney’s “father in art,” nurturing his talent and making sure he had pocket change. And then, in what Mr. McCraney considers a fluke, as a first-year graduate student he was tapped as an assistant to August Wilson, the acclaimed playwright, months before Mr. Wilson died.

Neither artist, though, is comfortable being labeled an exception. That is why the end of “Moonlight” is the part that veers the most from their lives. In the movie’s last act, Chiron goes to prison and ends up becoming a drug dealer himself. Yet, he is still a reflection of them — of Mr. McCraney’s struggle to be seen, of Mr. Jenkins’s struggle to feel worthy of being loved. But more, Chiron is the man, who, given their circumstances, Mr. McCraney and Mr. Jenkins should have become.

Of Mothers and Sons

The movie, at its heart, Mr. Jenkins said, is about how the relationship between a mother and son is fractured, and almost ruined, because of the crack epidemic, and the scenes between Chiron and his mother are excruciating for the men to watch.