Acharya Prashant explains that true youth is not merely a physical state defined by age, but a spiritual and mental quality. While physical youth is characterized by energy, dreams, and attraction to the material, spiritual youth involves the energy to cut through life's bondages, an attraction to ultimate beauty or divinity, and a vision for a higher purpose. He emphasizes that one can be spiritually young at any age, as this state is independent of the body and persists until one reaches the ultimate goal of liberation.