Consuming 20-year-old candy may not be safe. Over time, candies can lose their freshness and might become stale or have altered taste due to exposure to air, light, or moisture. Additionally, the ingredients may degrade, leading to a potential risk of bacterial contamination or spoilage. To avoid any health concerns, it’s generally recommended to discard candies past their expiration date, as they may not be suitable for consumption. I personally wouldn’t risk eating such old candy due to potential health risks associated with its age. Safety is crucial when it comes to food, especially if it’s significantly expired.