I agree in part that it's a C thing. More accurately it's an offset from the array base thing. The first element is at index 0 because its address is base + 0

I agree in part that it's a C thing. More accurately it's an offset from the array base thing. The first element is at index 0 because its address is base + 0 * sizeof(element) The second element is at index 1 because its address is base + 1 * sizeof(element)