It is very important that we learn to be thankful. For most of our lives, we are aspiring to have more. Many times are lives are spent chasing the next thing.... more money, a bigger house, an expensive car, nicer clothes, a better job, etc.
True abundance is when we recognize that everything is OK in our lives. The key, to adopting a status of gratitude, is to pay attention and be present in the moment. Be laser focused on "what is." Recognize that when you are truly thankful, all lack stops. You lack nothing at that moment in time. Your needs have been met.
Go ahead... try it. See what happens in your life.