This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Death And Ker
Igor's words to Minako following her confrontation with Geras, the ker of Old Age:
He was right. They will forget you. ... It's true that you will live in their hearts. They will remember your name, and that you were their friend. They will remember what you did. But someday they will forget exactly what you look like, or what it felt like to talk to you, or the sort of jokes you made. They will forget what exactly made you their friend – which of your qualities were their favorites. In a way, they'll forget that you were a living person and that you could have lived to be as old as them. It will become impossible for them to imagine what you'd be like if you'd lived. You will always belong to the past, a past that will grow farther and farther away, and have less and less to do with the present. Their minds will grow infirm, and may break, and all memory of you might vanish. ... But they will have still loved you.
Stuck in the high school building in the middle of the night waiting for a ker to turn up, Minako gives into the temptation to check her old profile in the school's social network. Among other comments (some of them highly unflattering) she finds messages from Junpei, Saori, Rio, Yuko, and Bebe left after her death - including a message less than a month old from Saori which reads simply, "Still missing you."
"I don't care what you said. This happened before, and it's not going to happen again. I'm saying goodbye this time."