According to legend, Jiang Taigong fished in the river Wei, hoping to meet a wise ruler. His hook was straight. When King Wen of Zhou found him and asked why, he said that the fish he wanted would come to the hook of its own will. King Wen took him as his teacher.
The saying 姜太公钓鱼，愿者上钩, “when Jiang Taigong fishes, the willing take the bait,” comes from this story.