Complaining and Being Discontent

Is Christianity boring, limited, and restrictive? Do we let the world convince us that they have something better to offer? Do they? How do we keep ourselves from complaining when we aren't happy with our circumstances. What can we learn from the Israelites complaining and inability to objectively look at the past and hopefully look towards the future.
The Israelites listened to the Egyptians talking about all the different kinds of food they ate freely in Egypt and they grew discontent with the monotony of the manna that the Lord had provided them for the last 13 months. somehow they had forgotten about the forced labor that provided them that "free" food. On the other hand, the food that God provided was truly free and it tasted like a sweet pastry. Also, they were on their way to the promised land which was flowing with milk and honey. Their limited state was temporary and full of God's grace and freedom.