Sometimes the repetition of it all, maybe without much gratitude being shown to us, can get very old. Once we start to quietly chafe at being unappreciated or taken for granted, our thoughts will soon turn more and more negative, and our happy, joyful, serving-God-through-others attitude will take a nosedive.
The battle, as always, is in the mind, and this is where we need to focus our attention. One good exercise will be to make ourselves remember how many mornings of our life God has awakened us to relatively good health, how often the Lord has let us enjoy the taste of food, or how many days He has kept us from having an accident on the highway.
May the Lord help us decide daily to be happy in His service.