It's the intense emotions and complex character dynamics. A story with yanderes often has high-stakes relationships and emotional turmoil, which can be captivating. Also, the element of surprise in their actions keeps the plot engaging.
The Sandman isn't real in the sense of being a living, breathing entity. In the Sandman real story, it's a fictional concept. It's a story made up to explain sleep and dreams, especially for children. Just like many other mythical creatures, it exists in the realm of imagination and stories, not in the real, tangible world. We can enjoy the stories about the Sandman, but we can't expect to meet him in real life.
Well, it's hard to say for sure. The real story has a lot of eyewitness accounts, but no conclusive proof. Some believe that the Mothman is real because so many people claimed to have seen it. However, others think it could be a case of mass hysteria or misidentifying common animals like large birds or bats.