Understanding the 11 benefits of practicing Metta along with mindfulness of the loveability of the difficult person and all beings can lead to happiness and freedom of the mind from annoyance.
The arising of the 5-hindrances is beyond our control. However mindfulness and wisdom applied to these hindrances can make a difference between being caught up in them and being free from them.
Use the acronym of M.A.I.N. (Mindfulness, Attitude, Insight and non-clinging) towards mindfulness of wholesome emotion can lead to development and maintain these beautiful states of mind such as generosity, lovingkindness, compassion, joy, happiness and wisdom.
