The world and life is a medium for actualization of karma.
rishis realized that the world, its perception, entire creation, is brahma. and realized themselves as brahma.
The perceptions of a person, the situation as s/he perceives facilitate realization, and thereby, dissolution of samskara.
rishis realized that the perceptions, the experiences, are manifestations, of and by brahma, manifesting and experiencing itself.
What is percepted, experienced, are drawings made by the perceiver, brahma, on the canvas of world, that is projection of itself.
What one perceives is individual to the person, though may be similar to that of another.
Words of Wisdom
The wisdom one finds in certain words are realization of wisdom within, the words serving as mere canvas upon which the wisdom is drawn by the person.
tat tvam asi
rishis realizing the perceived, the medium that facilitated the perception, and the perceiver to be the same, said- tat tvam asi