"When wisdom is developed and cultivated according to the fourth noble truth, it sees the secret of life, the reality of things as they are. When the secret is discovered, when the truth is seen, all the forces which feverishly produce the continuity of samsara in illusion become calm and incapable of producing any more karma formations, because there is no more illusion, no more thirst for continuity.

He who has realized the truth, Nirvana, is the happiest being in the world. He is free from all complexes and obsessions, the worries and troubles that torment others. His mental health is perfect. He does not repent the past, nor does he brood over the future. He lives fully in the present. Therefore he appreciates and enjoys things in the purest sense without self projections. He is joyfull, exultant, enjoying the pure life, his faculties pleased, free from anxiety, serene and peaceful. As he is free from selfish desire, hatred, ignorance, conceit, pride and all such defilements, he is pure and gentle, full of universal love, compassion, kindness, sympathy, understanding and tolerance. His service to others is of the purest, for he has no thought of self. He gains nothing, accumulates nothing, not even anything spiritual, because he is free from the illusion of self and the thirst for becoming."

What the Buddha taught - p.43