What cultural faux pas should I try to avoid making in Illinois?

We asked people in Illinois if they could share any humorous cultural blunders they commited. For new expats, keep in mind that these incidents are an inevitable part of expat life. Learning to laugh about them is the key!...

Other Questions:

•  What do I need to know before moving to Illinois?
•  How do I find a place to live in Illinois?
•  What is a typical expat home or apartment like in Illinois?
•  What is the average cost of housing in Illinois?
•  Should I buy or rent a home in Illinois?
•  What should I pack when moving to Illinois?
•  What cultural faux pas should I try to avoid making in Illinois?
•  Why do people move to Illinois?
•  What are healthcare services like in Illinois?
•  What are medical services in Illinois like?
•  What are typical rents in Illinois?
•  What appliances are typically included in a rental?