Classicly

Aesop was a Greek slave who lived during the 5th century BC, and his fables, like the "Tortoise and the Hare," the "Boy who Cried Wolf," and the "Goose that Laid the Golden Eggs," are known all over the world. They have been read to children as moral tales for thousands of years, and get passed on like a tradition, one generation to the next. It would almost be criminal to have missed these books as a child. Despite the credit attributed to Aesop, scholars have argued that these stories date back even further to the ancient Mesopotamians, who lived about 4000 years ago. If these fables where transmitted from so long ago, and an ancient Grecian slave wrote them down and popularized them, it's even more impressive: it means that the morals at the center of these tales are fundamental to humankind. Whatever your age, these simple tales are always a joy to read.