In this doctoral project, we will study strongly-correlated Condensed Matter systems (such as cuprate high Tc superconductors) and the effective theories describing their low-energy dynamics. These are complicated systems for which no microscopic theory is available, or even an effective theory, such as Fermi liquid theory. Yet, a number of recent experimental thermoelectric studies on overdoped cuprates made some headway in reproducing their results using a Boltzmann equation approach to transport. It is surprising that this should work, given the strongly-coupled nature of these materials. Boltzmann transport has a universal hydrodynamic regime, which can be derived in closed form in some cases. Could it be that the experimental studies are in fact only probing this universal, hydrodynamic regime? To answer this question, we will study the emergence of hydrodynamics from Boltzmann transport in a number of cases, starting from simple ones and moving on to more complicated ones closer to experiments, include the effects of disorder, and move beyond the relaxation time or semi-classical approximations by treating the collision kernel exactly or considering the Quantum Boltzmann Equation. Some of these questions will give rise to collaborations with Gaël Grissonnanche (Irradiated Solids Lab, IPP) and with Joerg Schmalian (Karlsruhe Institute for Technology, Germany).