When I was a little kid, my parents used to read to me before I went to bed. Though we covered a variety of "genres" (I use quotation marks there because I wonder how many genres there truly are in children's literature), my favorites were fairy tales and fantastical stories like The Wizard of Oz. That early fascination with fantasy and imagination has stuck with me throughout the years, and I still enjoy a good fantasy story or learning new folk lore or fairy tales.
When I was living in Japan, I learned a few folk tales just over the course of my work. The first one I remember coming across is this story called Urashima Taro (浦島太郎), that was in one classes' English reader.
To my knowledge there are slight variations to this story, but basically, the titular character is one day walking along the beach and spots some young boys tormenting a turtle. He takes pity on the creature and chases the boys away. To his surprise, the turtle thanks him, and to show his gratitude offers to take Urashima Taro to see the beautiful Ryugu Palace and meet the Emperor of the Sea. He accepts and goes with the turtle. When they arrive, he meets the emperor and his beautiful daughter, with whom he spends several days. Soon, however, he becomes anxious to get back home and check on his elderly mother. The princess is sorry to see him leave, but wishes him well and gives him a strange box as a parting gift. She tells him, however, never to open it. Taro returns home, but everything has changed. His home is gone, as are his mother and all of the people that he knew. Asking after his mother and if anyone knows his name, he discovers that he was said to have mysteriously disappeared 300 years ago. He then opens the box and with a puff of smoke he is transformed into an old man with a long beard. His old age had been inside.
...Well, so much for that.