There are many interesting cultural differences around the world. For example, in some subways in Saudi Arabia, the carriages are divided into single men’s cars and family cars. If a woman enters the men's carriage, locals might think she is violating customs; whereas on many European and American airplanes, if you sit in an aisle seat, you must stand up completely to let others pass. If you just turn sideways to let someone squeeze past, it might be considered impolite. Additionally, some international airlines do not board based on "who lines up first," but rather in groups according to seat zones. Even if you are at the front of the line, as long as your zone hasn't been called yet, you must wait nearby.

In the United States, tipping usually ranges from 15% to 20%; but in Japan, tipping can actually leave servers feeling confused. In Germany, being a few minutes late is considered very unprofessional; whereas in some Southern European countries like Spain, arriving a little late to social gatherings is quite normal. For example, in the UK, queuing is almost a "sacred" rule—no matter how long the line, everyone waits quietly in order.

Often, people tend to think others’ customs are "strange" or "troublesome," but it’s really just because everyone is used to understanding the world through their own culture. You might see it as efficient, but others might see it as offensive; you might see it as flexible, but others might see it as unruly. Over time, you realize that the meaning of travel isn’t just about sightseeing, but about constantly encountering these differences. After experiencing enough diverse rules, customs, and lifestyles, people gradually realize: there are no absolute "givens" in the world, and no single correct way to live. Perhaps the greatest meaning of travel is to gradually soften the arrogance of thinking "only I am right."