Does anyone know why the numbers are the gaps rather than the columns / rows? It's not exactly rocket science, but it took me a while to wrap my head around tha

Does anyone know why the numbers are the gaps rather than the columns / rows? It's not exactly rocket science, but it took me a while to wrap my head around that, and it would have felt more intuitive for e.g. an item taking up the first two columns to be 1/2 rather than 1/3. I wonder if that's something to do with being used to arrays starting at 0, and if it has to be columns then using 0/2.