As Lanterns continues to air on HBO, DCU fans are learning a lot about what it takes to be a Green Lantern, which has given many a new respect for Superman's Guy Gardner.
In Lanterns episode 3, we see exactly what John Stewart had to go through to be considered for the Green Lantern Corps. Since he was a baby, John had to learn how to be fearless and missed out on a normal childhood in the process. He devoted his whole life to becoming the hero even though the mantle wasn't promised to him.