We find that whenever there is an occasion, we are full of zeal and enthusiasm for that day. However this doesn't continue for long and we find ourselves getting caught with our old nature. We then give the excuse to ourselves saying, 'this is how I am, and this is my nature' etc. Once we start working with our old nature we cannot be enthusiastic anymore.
Each new festival is an occasion for us to finish something of the old. We only need to take a determined thought to remove something of our old nature. We no longer need to give excuses, but make the firm promise to ourselves to transform. Our zeal and enthusiasm will then never lessen and we will continue to celebrate with constant enthusiasm.