Different Manners
Eastern and Western cultures have different standards for what is acceptable and impolite. Although you are expected to tip in a restaurant in the United States, this is considered bad form in South Korea. In congested areas, pushing and shoving are also frowned upon.
People will excuse themselves and apologize if they accidentally touch you in Times Square, even if it is not a problem. But forget about it in South Korea. Pushing and shoving are not seen as insulting in this country. It is, after all, acceptable. If you’re a noticeable visitor, don’t expect to be treated differently. At the very least, you can do the same thing.