Probably the most important thing to remember when approaching the models taught in entry-level neoclassical econ courses (especially entry-level micro) is that the perfect competition and rational objective-optimizing agent assumptions do a ridiculous amount of the heavy lifting. Markets in real life often feature elements of oligopoly (or oligopsony, if it's a job market), strong EMH is a fairy tale, markets in equilibrium states (or equilibrium paths) are not welfare-maximizing, markets for commodified life essentials frequently feature highly inelastic demand, people are irrational and make decisions with incomplete information, stated preference is neither always transitive nor always endogenous (otherwise persuasive advertising wouldn't work!), local non-satiation implies people are infinitely greedy, and we're all dead in the long run.