Although the unusual structural, magnetic, electronic, and spin characteristics of manganocene has intrigued scientists for decades, a unified explanation and rationalization of its properties has not yet been provided. Results obtained by Multideterminantal Density Functional Theory (MD-DFT), Energy Decomposition Analysis (EDA), and Intrinsic Distortion Path (IDP) methodologies indicate how this uniqueness can be traced back to the manganocene's peculiar electronic structure, mainly, the degenerate ground state and close-lying electronic and spin states.