Getting used to the local food was the most difficult for me.  I'm a vegetarian, and seafood chicken processed meats are a very big part of life here.  I was warned before hand by friends who had been here, and it was very difficult at first.  My host mom made me sick a couple of times by slipping in things she didn't realize I couldn't eat, but we figured everything out and found several dishes that I like a lot and can eat.
The problem now is that I eat those same dishes everyday and am getting tired of it.