Subjects perceived as more challenging for UPSC aspirants often include Optional Subjects and General Studies papers that require critical thinking, such as Geography, Political Science, and Public Administration. The difficulty also varies based on an individual's strengths and background. Subjects that entail extensive theory or have vast syllabi, such as History and Economics, can be daunting. Aspirants may find it challenging to grasp complex concepts or interlink topics, particularly when dealing with current affairs and their historical context. This perception can lead to anxiety, necessitating effective study strategies.