The worst culture shock I ever experienced was when I went to Tijuana for a very short visit. I was a student in San Diego at the time and I went with a couple of friends to get a case of Coke in the 8-oz bottles, which we could only find in Mexico. We were greeted by many children, as we crossed the border, who were trying to sell us everything from key chains to flip-flops to blankets, you name it. There were many others just begging for any handout they could get. The streets were lined with rundown shops and night clubs; it was very busy and very noisy. We found the Coke and hailed a cab back to the border. That cab ride was the most terrifying thing I've ever experienced. The driver not only was gunning the old car at break neck speed, he wasn't going to stop for traffic in any intersection. I think we covered about 10 blocks, but it seemed like 30. We found ourselves sinking down in the back seat, because we couldn't bear to watch what was happening through the windshield. If he hit anybody or anything along the way, we did not want to know about it. ...more kids at the border, and we could not get back to the USA fast enough.