I believe I do have a timeline of events that you might find informative.
During his National Service with the British Army, Jerry visits a shop near to where he is posted in Germany. He meets Hilla, who is working in the shop.
Jerry’s original reason for visiting the shop was to purchase a rubber stamp that could replicate a mark that he shows on his hand. This mark is to prove that he has completed a cross-country run, a task which he wishes to avoid in future.
Hilla says that her father could make the stamp, but questions why he should help a British soldier. When Jerry asks if this is because her father is still sore about losing the war, Hilla responds: “No, Solomon Goldfarb is not sorry that Germany lost the war.”
After more back-and-forth between the two, Jerry comes to the suggestion that he should save his money on the rubber stamp and instead buy tickets to the pictures for Hilla and him.