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

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