Japanese people seem shocked when you can speak their language. They feel like it's incredibly difficult so when a foreigner says even one word to them they feel the need to give compliments on how well the foreigner spoke. This sounds very polite and can feel good in the beginning. After you're pretty good with speaking Japanese and have lived there awhile, it can get a bit annoying. At least, people working retail and service jobs in Japan are forced to treat everyone equally so they'll usually assume you can speak the language well until you show signs of confusion.