The 'Princess and the Pea' is a fictional story. Fairy tales like this often contain elements of magic and exaggeration, which are not typical of real - world historical events. Hans Christian Andersen used his imagination to create this charming tale about a princess so sensitive that she could feel a pea through multiple mattresses and feather beds.
Well, it's not a true story in the sense of being a historical account. It's more of a fictional story designed to teach a moral or just for entertainment. There's no evidence that there was ever a real princess who could detect a pea under all those mattresses in real history. It's part of the wonderful world of fairy tales where the impossible can happen and it's used to convey ideas like the importance of being genuine or the idea that true royalty has certain refined qualities.