A longstanding quest in cellular biology has been to decipher the quantitative laws governing the growth and division of individual cells, which are both inherently stochastic processes. While great strides have been made in unravelling and modeling the details of the gene regulatory networks involved in cell growth and division for different bacteria, there is a regrettable paucity of quantitative physical laws derived from the complementary “top down” perspective. In this talk, I shall first discuss why extraordinary advances in experimental techniques have been necessary to even establish that the sizes of individual bacterial cells increase exponentially with time, even as the population multiplies exponentially in numbers, under favorable conditions. Using our high precision single cell data, I shall then discuss what "scaling laws" for fluctuations in growth and division are revealed by them. Taking the minimalist "top-down" perspective, I shall then argue for how these scaling laws reveal the existence of a single cellular unit of time, which governs growth and division, not just in the mean, but also at the level of fluctuations. I will conclude by discussing the implications of these observations for the underlying biological systems design.