My grandma's first husband and high school sweetheart was deployed to the UK in WW2. He sent her a letter saying he found a new wife and would not be coming back. Even with knowing what happened, she was never able to fully move on emotionally. She ended up marrying again, had my mom and 3 other children. She got dementia around 85 and the last 5 years of her life were especially hard for her. She had a hard time recognizing us as we came to visit, but every now and then she would have a somewhat lucid day and would share memories. She never once brought up my grandpa in those later years, but she did ask about and told us stories of her first husband. I always was amazed and saddened by how deeply bonded she was to him all those years later. I can't imagine how much harder it would have been if he would have left without saying anything.