Zen is also known for its curious enlightenment stories, describing the moments the great Zen masters had their awakening. These stories are often difficult to understand, not because of the use of complicated jargon but because they are so surprisingly simple that it becomes hard to imagine how they contain any deep value.
Take, for instance, the following story. According to the Zen tradition, the Buddha once gave a sermon without words. Instead, he simply raised a flower. Only one of his students understood his message, smiled, and reached enlightenment.
How can this be understood? By raising the flower, the Buddha pointed to the suchness of existence (tathagata, meaning “reality being as it is”). Like all of reality, the flower has no meaning in itself and does not need meaning. The flower “just is.”
"The Great World History Book"