“Stupid is as stupid does.” The great irony of Forrest Gump was how insightful his simplistic sayings really were. Sort of the opposite of Peter Seller’s character in the classic movie, Being There. Everyone thought Chance the Gardener was brilliant but he really was a dolt, albeit (spoiler alert) a dolt who could walk on water.
In case you don’t know, Gump’s line means you are what you do. In other words, it doesn’t matter how intelligent you think you are or are supposed to be, if you consistently do dumb things, you’re still dumb.