"Heidi Can Use Everything She's Learned" is a classic book by the Swiss writer Johanna Spiri. The main character, a cheerful girl Heidi, lives in a mountain village and leads a simple but joyful life with her grandfather. Her life changes when she gets to the big city of Frankfurt, where she faces new challenges and meets different characters. In this tale of love, friendship and nature, Johanna Spiri carefully describes the beauty of the alpine nature, shading it against the background of the complex world of adults. The book "A person can use everything they have learned" evokes tender feelings in readers and inspires faith in goodness. It's a worthwhile adventure that leaves an indelible impression that true happiness can be found in the simple things."