Happiness and suffering come from your own mind, not from outside. Your own mind is the cause of happiness; your own mind is the cause of suffering. To obtain happiness and pacify suffering, you have to work within your own mind.

-Lama Zopa Rinpoche, "The Door To Satisfaction"

Every time a problem arises, the essential thing is to immediately
become aware that the problem comes from our selfish mind, that it
is created by self-cherishing thoughts. As long as you put the blame
outside yourself, there can be no happiness.

-Lama Zopa Rinpoche, "Transforming Problems into Happiness"