Before coming to Japan, I thought of ramen as a quick, extremely cheap and unhealthy food only eaten by broke college students instead of a quick, relatively cheap and extremely delicious meal suitable for kings and queens. 

And growing up in America, I thought that tipping was universally done (though not always liked), only to find out that it's practically unheard of in Japan. Try leaving a tip on a restaurant table and the wait-staff will chase you down to give you your money back.

These types of dualities are all over the place. They cause you question your beliefs and understanding, but in a good way. Derek Sivers put it best in this short TED clip: "Whatever ideas you may have or hear, the opposite may also be true".