Many times, we think that what we perceive is the whole world. When we walk more and more, we will find that the world is so vast, there are so many unknowns, waiting for ourselves. I met, just like my self-driving tour of Vietnam, from the cold autumn wind in the north, to the 20-degree Wenrunli in Guilin, to the Fangchenggang in the 29th degree, when walking on the bustling streets of the border of the port, Its a smile full of Vietnamese style.