In a 2011 study, psychologists from UC San Diego found that individuals who had seen a spoiler paragraph prior to reading a short story rated the story as more, not less, pleasurable. And that held true even of stories where the plot, the 'trick' so to speak, was seemingly the center of the experience, such as one of Roald Dahl’s signature ironic twist tales or an Agatha Christie mystery.
Why? When we know the plot, the twist, the surprise, we become more able to focus on everything else: language, character, the intricacies of rhythm and technique. We may even pay closer attention than we otherwise would, trying to wrestle with elements that we hadn’t even noticed the first time around. While it may seem that the surprise is the epicenter of the experience, that initial perception couldn’t be further from the truth. Focus too much on trying to figure out what the twist will be and you miss the art of the telling. Know the twist, and even if you’d previously thought that the knowledge would ruin your experience, you find your attention free to take in a much richer panorama than it otherwise would—and your mind enjoying itself far more as a result."
— Maria Konnikova, Scientific American