One of Sam's assignments was to write about his favorite bible story. his favorite was the about the whale, with the pirates who don't do anything. :)
In class, the few his teacher covered was Noah and the Ark, Jesus and the Cross, Jonah and the Whale, and David and Goliath.
So after hearing that last one, Sam says " I want to change my name to David" then he says to his teacher, "but you can call me Dave"