Modern DFT simulations of solids and molecules are typically based on the mighty plane-wave pseudopotential combination. Despite being numerically efficient, it does not allow for chemical conclusions unless the electronic structure is unitarily transformed into atomic orbitals. This primer for chemists and as well for physicists and engineers shows how to simply extract the chemistry and, hence, truly understand a plethora of real-world materials The goal of this humorous primer entertaining to read is to truly serve but not repel the reader. Recent in-person and also virtual summer schools in Europe and Asia have demonstrated the need for such a primer, also to be used for self-training