Well, I've had a look around e2, and noticed that no one has written anything on the supposed legend of how the Tao Te Ching came into being in the first place, and in the process explain a bit of about the Old Master's alleged past. It goes a little something like this:

According to certain historical records, Laozi's surname was Li, his given-name was Er, and his coming-of-age name was Dan. He was born in sixth century b.c. in Quren village, in Li district, Hu county, in the state of Chu.

Legend has it that he was appointed caretaker of the state archives under King Wu of Zhou, in the Zhou capital of Luoyang. Here, Laozi poured through innumerable books, absorbing the knowledge of the times, and gaining many insights into life. And in this way, Laozi grew wiser by the day.

In the twenty-third year of the Zhou King Zhao, witnessing the gradual decline of the house of Zhou, Laozi departed from Luoyang and jounrneyed westward through the Hangu Pass of the Great Wall. There, he met a man named Yin Xi, who was the gatekeeper at Hangu Pass. Yin Xi told Laozi of his intrest in the daoist arts, and persuaded Laozi to jot down a few notes on daoism for him. So Laozi wrote a short book in two parts, consisting of just over five thousand words. Upon finishing the book, he passsed through the Great Wall and was never heard from again.