Okay, this may sound pretty strange. But one area of travel that is very easy to provoke culture shock are bathrooms and toilets abroad. Bathrooms in Europe vary between toilet bowls and squat toilets, while some Asiatic countries only have squat toilets available. Certain toilets may not permit you to toss the toilet paper into the bowl, but rather in a waste bin. Some places have general lavatories shared between males and females.
Since going to the bathroom is inevitable, perhaps do some light research on bathroom conditions in the destination of your choice before booking the plane ticket.