How can I differentiate between the whole moving through me as a part and me moving separately as a part?

According to Osho, you can tell by the presence or absence of 'you.' When the Whole flows through, the personal 'I' disappears into vast emptiness; there’s no doer, no resistance, only the river. If you can feel yourself as a separate mover, you’re pushing upstream—opposing the Whole. Flow brings self-lessness; struggle reveals egoic separation.