Zhang Liang
The old man came back after walking a distance and praised Zhang Liang, "This child can be taught!" and asked Zhang Liang to meet him at the bridge again at dawn five days later. Zhang Liang was confused but agreed. Five days later, Zhang Liang rushed to the bridge at the stroke of dawn but the old man was already waiting for him there. The old man chided him, "How can you be late for a meeting with an elderly man? Come back again five days later!" Zhang Liang tried his best to be punctual the second time but the old man still arrived earlier than him, and he was scorned by the old man once more and told to return again five days later. The third time, Zhang Liang went to the bridge at midnight and waited until the old man appeared. This time, the old man was impressed with Zhang Liang's fortitude and humility, that he presented Zhang with a book, saying, "You can become the tutor of a ruler after reading this book. Within ten years, the world will become chaotic. You can then use your knowledge from this book to bring peace and prosperity to the empire. Meet me again 13 years later. I'm the yellow rock at the foot of Mount Gucheng."