Maybe you didn't remember it with your heart. I have read many novels. As long as I tell the story, I know if I have seen it, but I can't name it. Maybe these things are filtered out by our consciousness because they are not important. So it's not about memory.
You can consciously strengthen your memory.
For example; Chunking strategy, strengthen the practice of memory, choose appropriate time memory, and avoid proactive inhibition and proactive inhibition. Wait a minute.