Claims

We perceive the universe to be 3-dimensional because at human scales the volume of a ball grows as r^3 (cubic growth), but the universe is not inherently 3-dimensional; in the early universe it may have been higher-dimensional, and as the universe evolved it became lower-dimensional, with dimension being an emergent property of the scale at which you're observing.

The fundamental laws of physics appear to be fine-tuned to permit complex structures like atoms, molecules, and life; we do not yet have an explanation for why the mass of the electron, the proton, and the neutron have the specific values they do, or why the strengths of forces allow for stability and complexity.