Well, how can you go on forever without falling off the edge of the Earth? The surface of the Earth two-dimensional, and approximately flat... but there&#x27;s small positive curvature, so you&#x27;re continuously wrapping around to a different part of the space. The surface of the Earth can be meaningfully understood as a two-dimensional surface that possesses finite dimension.<p>A three-dimensional space can be close to flat but have positive curvature as well (or negative curvature, for that matter). Some proposals give our universe positive curvature, rendering its space finite, though still stupidly-big. (I&#x27;m not aware of there being a final word on the subject, though). And if different dimensions can have different curvatures, some of them could be much smaller than others.