Are you aware of the different levels of Gratitude? As you are probably know(although you may not have thought about it much), gratitude is not simply a binary feeling. You are not either Full of Gratitude or Not full of Gratitude. There are various levels that you can be at within this broad spectrum of feelings.
The first level of gratitude could be thought of as Being thankful for things in our lives. This is at a conscious level. Listing out the 1,001 Things that bring me more gratitude is at this level. I am consciously listing physical and material things, people, and events that I am grateful for. It requires me to think of the various things in order to list them down. This is not a bad level to be at for it puts me in a mindset of gratitude.
The more I am in the mindset, the easier it will be to re-visit this level. Being grateful is a skill that you can develop. Just like playing a sport, the more you practice, the better you will become at being grateful.
The extreme level of gratitude would be when you evolve into a Grateful Being. (In this case, extreme is not a bad thing). At this level gratitude encompasses everything we do; we eat, sleep, drink, talk, walk, and exude gratitude. With each sub conscious function, we feel grateful. Gratitude is not only a part of our life, but it IS our life. Achieving this state takes practice; it takes a lot of it for most people.
You are probably somewhere in-between these two states. Enjoy where you are, determine where you want to be, and move in that direction.