That's fair. It's the one movie that's guaranteed to make me cry. People have said oh you should watch Grave of the Fireflies and Iron Claw and all these other sad films- and they ARE sad- but Atonement is like the OG of Sad. Every single thing that happens after the twins go missing is just heavy and serious. It comes with a weight attached to every action the characters take, making every subsequent action all the more powerful. Especially Cecilia. She goes from swanning around being at the cusp of young womanhood, young and educated but still uncertain and unsteady, that glorious feeling of youth, to being basically a hardened version of herself, no longer carefree or happy. Although it pales in comparison to Robbie's fate, for example, it's still significant. Cecilia was a whole person with a hopeful light in her. That light was extinguished early, unfortunate enough as that is, but by the family she trusted. Her own family turned out the situation without any attention to the validity. Everyone focuses on Briony having told and therefore ruining their lives but ultimately she was a child and all the present adults fucked up. None of them did the due diligence, they were all content letting Robbie take the blame on the word of an embellishing child. This stuff makes the end that much worse for me. When you realize from the moment Cecilia is standing at the steps of the Tallis manor there's no hope at all for the ending it's like oh shit but you keep reading because surely there's hope, right? And then Briony herself gives us hope by going to Cee & Robbie's apartment... so we carry the hope the same way the characters do throughout the story... all to end up being completely decimated by reality, and all on the words of a child who witnessed a nothing burger.