Every physics student knows the euphoria of seeing "assume ideal conditions" on an exam question. It's basically code for "we're ignoring all the messy real-world complications!" But when the professor hits you with "you cannot assume ideal conditions," that's when your soul leaves your body. Suddenly you're accounting for air resistance, friction, non-uniform density, and probably the butterfly effect in Madagascar. It's like going from "spherical cow in vacuum" paradise to "calculate the exact trajectory of this irregularly shaped cow falling through a hurricane" nightmare.