If we take the 3 examples from above: glass, diamond, and bone, we can examine the concept of anti-fragility a little closer. Glass will break if it is dropped, thus, it is fragile. Diamond is nearly unbreakable, but doesn’t get any better from stress and therefore doesn’t care, so it is deemed robust. Human bone on the other hand, gets stronger from the right amount of stress and in fact, needs it, otherwise it atrophies leading to problems such as osteoporosis.