Tear Jerker / Miss Pettigrew Lives for a Day

• The song number "If I Didn't Care". It clearly pains Delysia to sing such a song when she's still heartbroken over Michael. It morphs into a Heartwarming Moment as, through the course of the song, she realises she does love him.
• Also the quiet exchange between Miss Pettigrew and Joe, the oldest characters in the movie who lived through World War I, when the "young set" are pointing excitedly at the planes flying overhead:
  Guinevere: They don't remember the last one, do they.
  Joe: No. They don't.
• Later, they watch the spotlights in the sky above the club, and ask each other if they lost anyone in the Great War.
  Joe: Damn near every school friend I had.
• Guinevere describing The Lost Lenore she lost during the war; she says he didn't make very much money but "he smiled whenever he saw me, and we could have built a life on that."
• There's also the parting between Miss Pettigrew and Delysia. Although the latter is going off to a better life with Michael, it's likely that this could be the last time they see each other. The following scene of Miss Pettigrew walking into the train station alone is quite bittersweet.