The standard approach to cosmology is: 1. Construct an overly simplified model. 2. Deduce its general relativistic consequences (Friedmann's equations). 3. Observe that they do not correspond to the real universe. 4. Invent increasingly many "amendments" (LCDM: dark energy, dark matter + additional free parameters) to save the model. We, instead, point out that full nonlinear gravity itself has the potential to explain cosmological observations without the introduction of hypothetical ingredients. This essay hopes to communicate the necessity of taking seriously the real, observed, "lumpy" universe and the resulting automatic nonlinearities of general relativity, instead of allowing an oversimplified "smooth" cosmological model to perpetuate a consensus worldview of a universe allegedly dominated by mysterious "dark", and never seen, components.