Bhagavad Gita, Chapter 6, Verse 27

Verily, the supreme bliss comes to that Yogi, of perfectly tranquil mind, with passions quieted, Brahman-become, and freed from taint.

Real, lasting happiness here isn't separate from how someone actually sees the world around them.

Several qualities are named together, a calm mind, subdued passions, seeing everything as connected to God, none of them optional. Real joy, in this picture, comes from that whole combination, not any single piece alone.