In this paper we discover intrinsic problems of microscopic theories of superfluidity/ superconductivity developed by using single particle basis with plane wave representation of particles. Such theories are found to be inconsistent with certain physical realities attained by the system in its low energy states and they cannot reveal complete and clear understanding of the said phenomenon with experimentally matching results. Here we also conclude that pair of particle basis is more appropriate for developing the micro-scopic theories of widely different systems such as liquid 4He, liquid 3He, N−conduction electrons, etc. which exhibit superfluidity/ superconductivity at low temperatures