Conceptual Metaphor Theory (CMT), proposed by George Lakoff et al., refers to understanding one idea, or conceptual domain, in terms of another. Conceptual metaphor is crucial in the organization of human experience and abstract thinking. CMT has been used as a framework to form interdisciplinary studies. Thus the theory has been expanded through different fields and formed new approaches to analyze old problems in various disciplines such as literature, psychology, and alike. However, this lecture focused on a few methodological restrictions of CMT, such as using limited examples from English, mainly based on intuition, being inattentive to linguistic data from other language families, and restricted use of corpus-based studies. In addition to those methodological restrictions, terminological and conceptual challenges reduce the precision of analyses within this framework. Borders between conceptual metaphor and terms and concepts such as the following are widely uncertain: perception verbs polysemy, metonymy, physiological metaphors of emotion, and synesthesia. The data to show these terminological challenges have been gathered through long-term research on Persian Language Data Base (PLDB) and Persian language literature prose and poetry.