The Buddha’s most important teaching was the correct application of concentration through mindfulness. This is a subject that is very subtle but also very important to the realization of happiness.
In order for us to overcome suffering we must learn to understand it. On a basic level, the natural world is not complicated — it operates on the basis of certain laws which can be observed by one who is interested in noting.
What is required is a consistent interest acknowledgement. While right mindfulness is mentally noting or labeling what happened, right concentration is the habit or tendency of doing so repeatedly so that each moment that arises is noted distinctly.
In other words, right concentration is repeating the explicit acknowledgement. As the object of the mind changes, so too does the label so that each distinct moment can be labeled and discerned individually, separate and apart from the moments which came before or the moments which might follow.
The subtlety I mentioned is in distinguishing this right concentration from attachment to a particular condition of the mind or feeling which can arise if the noting is sparse. If we are seeking a particular sense experience then, by definition, we are unwilling to truly observe what is actually happening.
As long as we are grasping for something different than our current experience, we will always suffer from the desire of wanting more. Conversely, each moment labeled on its own is satisfactory.
The beauty of the Buddha’s teaching is that, when applied correctly, we don’t have to get anything more to be happy. Happiness is already in front of us and we are simply encouraged to begin experiencing it.