Funny after two months in SE Asia we found a McDonald's on Bali where we stayed for 4 days. We ate there two days in a row just to feel a bit "normal" again. Then while back in Thailand we scored a jar of peanut butter and experienced the same feeling of joy. After that we were fine again until the end of our adventure.
Doing normal things stops culture fatigue, the longer we live abroad , the more we need to adapt, the more fatigued we become. Familiar, routines help us to adapt to cultures. http://hobotraveler.com/travel-journal/cultural-fatigue.html