This essay traces Girard's intellectual journey and shows how his central insight-that human desire is fundamentally imitative-not only shapes personal identity but also leads to rivalry and conflict. It begins by explaining the triangular structure of desire through the relation between subject, object, and model, and develops Girard's distinctions between external and internal mediation, mimetic rivalry, contagion, and metaphysical desire. It further demonstrates the relevance of mimetic theory to consumer culture, social media and political polarization. Finally, the article offers a critical appraisal, highlighting both the interpretive power of Girard's framework and its limits, especially its tendency toward universalization and reductionism.