When I was a sophomore in college I was running low in funds and one more quarter of school wouldn't buy me anything, so I spend my remaining funds on a trip to Europe. In Germany I met two young American women who were just a few years older than I was. They were roommates and both working there. They suggested I make a stop in Cologne to visit. I did. I recall having to bathe in a portable bathtub in the living room of their apartment.
We went to dinner at a restaurant they suggested. They'd mentioned that there had been some problems with tainted food, but that had cleared up. From the restaurant I took the train to Frankfurt to board my flight home. A couple minutes before boarding I started feeling queasy, but it was too late to back out. Once on the plane the heaving started. I needed to drink water, but they had no safe water on the plane!! I heaved for the whole flight. I felt so bad for the woman seated near me. She was a German woman and very stoic about it. From that day on I've not been able to EVEN THINK about eating German food.