The use of the imperial system for measurements, including inches, feet, and Fahrenheit, rather than the metric system (centimeters, Celsius), is often perplexing to those accustomed to metric units.
The expectation of tipping in various service industries, such as restaurants and taxis, can be confusing to visitors from countries where tipping is less common or not expected.
The generous portion sizes in American restaurants often surprise visitors from countries where meals are typically smaller. The "super-sized" culture can be overwhelming.
The complexity and indirect nature of the US electoral system, particularly the Electoral College, can be difficult to grasp for those accustomed to more straightforward voting systems.
The intricacies of the US healthcare system, including the private insurance-based model and the high cost of medical treatment, can be perplexing to those accustomed to universal healthcare systems.
The widespread availability of firearms and the importance placed on individual gun ownership rights can be difficult to understand for people coming from countries with stricter gun control laws.
The practice of not including sales taxes in the displayed prices can confuse visitors, as they need to calculate the total cost of an item at the checkout.
The reliance on personal cars and the prevalence of driving as the primary mode of transportation, even for short distances, can be surprising to individuals from countries with extensive public transportation systems.