Abstract: A major theoretical insight of the last century was that strict renormalizability can serve as a powerful criterion for selecting Lagrangians in perturbative quantum field theory. The Standard Model (without gravity) is strictly renormalizable from a perturbative point of view. On the other hand, the inclusion of gravity seems not to respect this criterion, since general relativity is perturbatively non-renormalizable. The aim of this talk is to provide concrete evidence that strict renormalizability remains a valid and useful selection principle even for gravity. First, I show that adding quadratic curvature terms to the Einstein-Hilbert action yields a unique strictly renormalizable quantum field theory: quadratic gravity. Second, I demonstrate that this theory is not only consistent but also highly predictive, describing new physics beyond general relativity even below the Planck scale. In particular, it provides one of the best fits to CMB anisotropies via Starobinsky inflation and makes cosmological predictions that can be potentially tested in the next decade. I conclude with open questions and a historical perspective.