The joy of letting go includes restraint expressed as sitting with integrity as well as letting go of stories, expectation & experiences. This letting go is not a sacrifice but rather releasing the burden of holding onto the things that cause us suffering.
The Seven Factors of Enlightenment are mindfulness, investigation, energy, joy, calm, concentration and equanimity. When brought to fruition they lead to the highest happiness we can experience. How can we cultivate these qualities consciously in our meditation practice and in our life?
What keeps our heart from expressing pure lovingkindness? Understanding "tanna" or clinging, that gives rise to attachment & aversion, is the obstacle.