When one becomes brahma-bhūtaḥ, self-realized, at that time, he becomes prasanna-manaso, joyful. Na śocati na kāṅkṣati: he has no more lamentation or hankering. Evaṁ prasanna. In this state of life, prasanna-manaso, evaṁ prasanna-manaso bhagavad-bhakti-yogataḥ (SB 1.2.20), by practicing bhagavad-bhakti yoga, bhagavat-tattva-vijñānaṁ mukta-saṅgasya jāyate. At that time, one can understand what is the science of God, bhagavat-tattva. It is not a sentiment; it is a vijñāna, science.