What does Will remember happened when he went to Claire's the evening of September 10?

Will remembers that when he went to Claire's he tried to decide how to talk to her. When he was deciding whether to knock at the front door or try to throw stones at her bedroom window, she came outside. She was looking for her cat. Will apologized, and she told him he did not do anything wrong and did not need to apologize. He helped her find her cat. He apologized again, and she went inside.