There are a lot of fascinating unsolved mysteries out there, and in some cases it’s because people died withholding important information. Whether Benjamin Franklin never revealing the identity of his son’s mother, Ludwig van Beethoven writing letters to an anonymous “Immortal Beloved,” or Maurice Ward inventing a heat-resistant plastic called Starlite but never revealing the formula, these are HUGE secrets people took to the grave. WatchMojo counts down ten of biggest secrets we’ll never get the answers to.