A man walks in the desert for 7 days, he turns around and finds no footprints, How can this be?

This weekend we traveled into Yueyang and visited some of our foreign friends. We ate out, toured there schools and even went to a couple of clubs. The first club was fun, We sat down and played a game that seems to be at everybar ( its a cup with dice in it, each person has to guess how many numbers everyone else has) After a few rounds we turned around and in walks about 10 other foreigners. Weird. Our organiztion always told us if you want to find the foreigners they will be at the bars. Now we believe them. We met 1 guy from the Netherlands and the other from Germany. They worked at a factory doing some sort of exchange program. Not sure what that means.
The next bar we went to was a little crazy. Strobe lights everywhere, and laser beams going crazy. There were stages with girls dancing on them too. It was a little weird I have to say.
Espiecially when all the lights went flashy and I decided that I was glad I wasn't epileptic. We left shortly after the flashy lights deciding our eyes couldnt take it.
It was a fun time and we ended up staying at another friends apartment in Yueyang.
It was defiently nice to just hang out with americans and find out what all they were going through. We even found out that one friend is now dating a guy in our organization! So now we are not the only couple!
Today we were invited to our chinese friend amanda's home for lunch. Her father made dumplings, Wan Zi, ( a pork rice ball, that looks like a meat ball) beef, pumpkin, and lots of other delicious foods. Amanda's family also makes there own wine. She showed us these huge bottles and explained the process. They are half ba jiu and half grapes. Then I noticed something on the bottom of one and relized it was a sea horse. I told Joe he was drinking sea horse wine and he was like, well when in china, do as the chinese. Amanda said that this wine prevents cancer.
SO they laughed at us because we dont believe them that seahorse is a medicine.
They then invited us for dinner too, Her father really made way too much food. So later that evening we went back for meal #2. Everything was the same except we also had pig kidney. Mmmm everything I have always wanted. It's actually not that bad. With the sauce it is cooked in, its actually good. Her father continued to check to see if we could take the spicyness.I think both Joe and I have adaped. The kidney wasnt that spicy at all.
We then came home and ran for about twenty minutes around the track outside our apartment. Its funny to run at night in the pitch black here. There are many people and most of them are doing there evening exercises, usually walking. The best part is watching them walk backwards. Chinese believe , or so we are told, that it is good for your kidneys, well we have actually been told by two different sources that its either good for your kidneys or your heart. Both sources dont believe each other. Point is, its good for something, even if it might just be to make your butt look good ( this is my belief). Everyone is walking backwards in the pitch black. Its so crazy, it looks like a zombie movie where everyones head got turned around or something and they're all walking toward you!! Spooky!
Now we have decided to try and walk backwards a little too. We walk one time around the track after our run, backwards.

no footprints?, he walked backwards