Krishna touches on something delicate here. Not clinging to son, wife, or home. This does not mean abandoning relationships. Love your family, but do not let that love become a chain. Care deeply, but hold lightly.
And when pleasant things come or unpleasant ones arrive — whether you get what you wanted or lose what you cherished — let the mind remain even. This equanimity is another mark of knowledge. Deep below a lake's surface, the water stays still even when a storm rages above.