Whatever happiness one derives inwardly from the Self, by not clinging to and associating with the objects around, the same happiness in interminable measure he gets on identifying with Brahman (and gaining the resulting expanse).
Krishna describes how spiritual wisdom leads irresistibly to its climax of full expanse, from Atma (embodied Self) to Brahman (universal Self). To begin with, it is a centric effort, focussing on the blissful Self. Once this is gained, the seeker gallops to imbibe universal expanse. Whatever senses perceive is but a visible display of the invisible Self, Atman, in Braahmic dimension.
Whatever happiness the yogi derives from absorptional meditation gives place to a widespread inundation. Inner Consciousness alone displays all perceptions. Hence there are no distinctions like internal and external, subtle and gross. All are but notions, floats, in Consciousness, which is neither matter nor energy. Matter and energy too are manifestations of the same Consciousness.
No more is the need for absorption, which would imply permission for the fictitious two! All that is gone now. The yogi becomes all-filling Consciousness for ever.