The phrase 随心所欲 is formed through a classical, almost poetic layering of concepts to paint a complete mental picture. It begins with "随" (to follow) acting upon "心" (the heart/mind), establishing the source of action. This union, "随心", then flows directly into the realm of "所欲" (that which is desired), creating a cause-and-effect chain. The entire construction visually and conceptually maps the journey from inner inclination to outward fulfillment, capturing a philosophy of action in a single, fluid expression.