Weird things that only happen in the U.S.
First of all, I want to make clear that I speak from my own experience, the U.S. is a huge and very diverse place where many things change from a state to another.
That being said the first weird thing I want to mention is the size of everything, I come from Europe so when I first came to the U.S. I was shoked by the size of roads, schools and buildings in general, but the biggest of all is food.
If you go to a restaurant you better be hungry, the amount of food served is so massive that the waiter/waitress asks you if you want a container to take home the food you couldn't eat (you also get free refills which its really nice).
Also something that was weird to me at first are the tips, the service in restaurants in the U.S. is extremely good but it has a cost, a huge one if you go out to eat with a lot of people, because is expected from the customer to pay at least a 10% of the price of the food in tips and it can get expensive.
One thing that drives me nuts and that I still don't get used to is the price tags, every state has a different tax applied to the goods bought (ex. Wyoming 4%, California 7%), and because of this when you go to buy something you see the price without tax and after they apply it you end up paying more than expected.
The last thing I will mention is about school, in my home country the students are really restricted when it comes to eating or using the restroom during class, compared to the U.S. you can eat, drink or use the restroom and its perfectly fine. This for me was a big surprise and I surely am enjoying it!