Why is it not possible to lie on one nail?

Lying on one nail is not possible because the pressure exerted by the body on a single point would be concentrated on that small area, causing extreme pain and potential injury. The human body requires a distribution of weight to avoid sharp pressure points, which is why it’s more feasible to lie on multiple nails arranged in a flat surface. This distribution allows the weight to be spread out, reducing the risk of injury and discomfort.