Would you want to know when you're going to die? I've thought about this question quite a bit recently.
Several months ago, I picked up a new novel titled "The Measure" by Nikki Erlick, which opens with quite the plot twist. One morning, everybody on the planet (ages 22 and up) wakes up to a surprise at their front door: a small wooden box, personally engraved, with the words: "The measure of your life lies within." Each box contains a string whose length determines the length of the recipient's life.