What is the most intense culture shock you have ever experienced?

Moving from the United States to Japan was the most culture shock. Here are a few examples that blew my mind:

The trains are really silent! Except for a few quiet conversations, everyone is either on their phones or minding their own business. This is in stark contrast to the NYC subway, where people are having loud discussions, chatting on cell phones, playing instruments, and generally being as loud as Americans. After a few months in Japan, I can even tell who is new to the country based on how loud they are on the train.

Children can travel on their own! Every day, I see four-year-olds riding the train to and from school, crossing the street with their hands raised so drivers can see them. If you released your four-year-old loose on the streets of Los Angeles for even five minutes, people would accuse you of being insane.

At 7–11 a.m., I pay my energy, phone, and water bills. Stuff sounds strange because I accomplished all of that online back in the States.

Walking and biking. I seldom ever drive here because the public transportation system is so excellent. I have a little car, and I've only filled it up twice in the six months I've been here.