Love, longing, and lamentation form the central thematic variables of Keats’s poetry, through which the study explores the relationship between desire, beauty, transience, mortality, and personal experience. Love is manifested as emotional attachment, physical desire, intimacy, and the desire to be permanent, and longing manifests as separation, unfulfilled desire and the impossibility of maintaining happiness. Lamentation is disassociated from individual song and point-of-view or singer to convey a sense of melancholy, suffering, loss and consciousness of mortality, which are related to issues raised by the Romantics. The study is aimed at analysing these themes through a qualitative, descriptive and analysis with secondary sources and selected poems in relation to Keats' poetic vision and his personal experiences. The results show an ongoing conflict between desire and fulfilment, beauty and decay, permanency and transience, aspiration and limitation. The discussion illustrates how Keats's personal feelings are elevated to a universal observation on human fragility and poetic sublimation. The study suggests a fuller comprehension of various concepts of Keats Romantic imagination, and its disadvantages consist of qualitative analysis, secondary source on one hand and selected poems on the other. Future study can use broader textual selections, comparative readings, and interdisciplinary approaches.