Adapted from BBC
Paper, seemingly completely harmless, can be a weapon in disguise: paper cuts hurt way beyond expectations.
It’s all to do with nerve endings. There are a lot more pain receptors in your fingertips than almost anywhere else in your body, which explains the intense fiery quality of finger paper cuts that are worse that than deeper cuts on the arm or the thigh. They don’t slice that deep into your body, which is perhaps why it’s puzzling that they should hurt so much. But it’s exactly for this reason that paper cuts hurt bad. A deeper wound would result in bleeding. The blood would clot and a scab would develop protecting it from the environment. The shallow wound of a paper cut doesn’t get the same cover, leaving the injured nerve endings exposed and more irritated.
Having said that, nobody has ever proven that this is the case, but it is a reasonable hypothesis. Don’t you agree?