When it comes to understand how a cohesive object breaks-up, there are two types of temptations: either seek for detailed mechanisms (capillary instabilities for drops, cracks propagation in brittle solids, for example) and their articulation with external constraints, or rely on a general principle, like a conservation principle for instance, to infer the multiplicity of the fragments sizes. Microscopic descriptions often overlook the question of the sizes distribution, and the uncontrolled use of conservation principles leads to notorious mistakes (see §11 in JFM 898, P1, 2020).

I will argue that a well chosen principle, coupled with a geometrical constraint, helps at understanding why a breaking object fragments into many more small pieces than bigger ones (think of a glass dropped on the floor), in a fashion which is sensitive to its initial shape. Examples including exploding liquid shells, crushed brittle materials, plastic debris in the ocean, and remnants from the cavemen industry will be discussed.