ब्रह्मभूतः प्रसन्नात्मा न शोचति न काङ्क्षति।समः सर्वेषु भूतेषु मद्भक्तिं लभते पराम्॥
brahma-bhūtaḥ prasannātmā na śocati na kāṅkṣatisamaḥ sarveṣu bhūteṣu mad-bhaktiṃ labhate parām
Word by word
The verse says
Having become the absolute, clear in himself, he does not grieve and does not want. The same towards everything that lives, he comes to the highest love of me.
In plain words
The fourth verse, and it ends somewhere unexpected.
You would think this is the destination. Clear, grieving at nothing, wanting nothing, the same towards all beings.
And then the last line says he comes to the highest love. Which means that state was not the end. It was the condition for something else beginning.
Where you've felt this · in growing older
Your aunt looked after her husband for a long time when he could no longer get about. She says the odd thing about those years was not how hard they were. Somewhere in the middle she stopped wanting anything to be different. That was when she started enjoying his company again, the way she had when they were young.
Going deeper
Love arriving after the state of equanimity, rather than before it, is the surprising order here and it changes what the whole book has been building.
One reading of the Gita has it climbing towards a calm, unmoved condition in which nothing touches you. This verse puts that condition in the middle of the sentence and keeps going. What it leads to is bhakti - devotion, love - described as the highest.
That is strange only if you assume equanimity means not feeling. What it actually removes is wanting and grieving, which are the two things that make love into a transaction. Take those out and what remains is not coldness; it is the first chance at affection that is not asking for anything.
So the steadiness this book keeps recommending is not the point of it. It is the clearing of the ground, and the thing it clears the ground for is warmer than itself.