In the Netflix movie “All the Bright Places,” based on Jennifer Niven’s 2015 novel and directed by Brett Haley, audiences are introduced to the high school student Violet Markey (Elle Fanning) just as she’s staring down at the edge of a bridge, contemplating the value of her life. It is at that moment when Theodore Fitch (Justice Smith), a stranger who happens to be jogging along that same overpass, encourages her to step back.