First, they might experience culture shock in a different period. Some people have most difficulties in the first couple of weeks, others only start to notice culture shock after a couple of months.
Second, they might be experiencing culture shock at the same time as you do, but are too shy to talk about it with other people. Fortunately, there is one certainty with culture shock: it does not last forever! You will get used to your new surroundings and learn to appreciate them.