Luca tells a story of a boy named Luca who was in the pursuit of knowledge. Rumour said that there was a temple with the shape of a pencil representing knowledge hiding within an ancient citadel. One day, Luca found the way into that citadel but suddenly all of the waterfalls started to pour down and raise the water level to cover the temple. From here, the boy had to hurry to the temple not to miss out the chance to acquire the knowledge hiding within. The story conveys the message of time limitation for knowledge acquirement. Among the sea of knowledge with thousands of things to learn, we must point out a clear path to only absorb meaningful ones and avoid wasting time on meaningless ones.