Having lived in the USA for almost one year now with my family, we have definitely become Americanized in many ways. Here is a list my family came up with:
You know that you are living in the USA when...
💬 you don't respond to sentences like "How's it going?" or "See you soon!" with more than a few words.
💵 the tip you leave at a restaurant is worth another meal.
⚾ you are interested in sports like baseball, American football, or basketball, even though you might have never watched these games before.
🛒 you love your Sunday shopping trip to the mall, Walmart, and any other store, and start questioning how you'd survive Sundays in Germany without any stores open.
🚗 you consider a 10-hour-drive to another state over the weekend as totally reasonable.
👨⚕️ you are (still) highly confused about your American health insurance and its (missing) coverage.
🍩 donuts, bagels, and bread are science: where you buy them or whether you eventually make them yourself.
💡 Any other ideas you would like to add?