Continuity mistake: When George sits down with Mary on the Davenport in her house's parlor, her left arm is in her lap, then the scene quickly cuts, showing her left arm now resting on the arm.
Continuity mistake: George walks downtown to find Mary. He stops in the street as a man is walking the opposite direction. The man doesn't pass George at any point. The scene cuts to a closer angle and he has disappeared.
Continuity mistake: George throws a rock at the dilapidated house. He is talking about his wishes. Mary starts to turn in one angle and repeats the action in the next angle.
Continuity mistake: When George comes downstairs to eat with his parents, there's a lot of commotion including a barking dog. George looks down at it and the scene cuts instantly to a wider shot. He is no longer looking down.
Continuity mistake: When George is trying to open the gate to Mary's house, the walking stick in his right hand is pointed up, but the next shot it's pointed down.
Continuity mistake: The walking stick carried by George as he wrestles with opening the gate to Mary's house is raised up in the closeup shot, then immediately down in the long shot when he finally is able to open the gate.
Continuity mistake: In the run on the Building and Loan scene, Ernie approaches and stands close to Mary's left shoulder, but the long shot of George confronting the crowd shows Ernie further away from Mary and partially hidden by a column in the office.
Continuity mistake: In the drugstore scene, young George is holding up his latest issue of National Geographic magazine for Mary to see, but the next shot shows George bending down to fill Mary's ice cream dish.
Continuity mistake: At the beginning in the soda shop, the first little girl (Mary) is facing toward the camera, away from the other girl that comes in. When they start talking however in the next shot, both are facing outward.
Answer: It was a common phrase at the time, like someone saying "oh boy!" or "hot damn."