Acharya Prashant clarifies that while Yoga Day is celebrated globally, the modern interpretation focusing solely on physical postures and exercises is not India's greatest contribution. He explains that the true essence of Yoga must be understood through the lens of Vedanta, which is the heart of the Vedas. Real Yoga signifies the union of the mind with the Atma, which represents the purest and highest state of the mind. India's most significant gift to the world is the realization that the ultimate truth and power reside within one's own purified consciousness, rather than in external deities or physical rituals. The speaker emphasizes that the mind is often a prisoner of its own patterns, and true Yoga involves liberating the mind from these bondages to reach a state of stillness and purity.