Buzz
There are a few factors involved here, some related to the paper and others to your skin.
For one, which part of your body encounters paper most often? That's right, paper cuts mainly occur on your fingers and hands. These areas are complex sensory tools, packed with nerve fibers called nociceptors. These nerves detect temperature, pressure, and pain, and there are more of them in your hands and fingers than in most other parts of your body. Because of this, injuries to your hands are felt more intensely than in other areas. A similar paper cut on a less nerve-rich area like your leg wouldn't send nearly as many pain signals to your brain.
To make things even worse, you can't just stop using your hands every time you get a paper cut. You need to touch things and pick things up, so while the cut heals, the skin keeps moving. The edges of the wound get pulled apart, slowing the healing process and keeping the pain lingering.
Okay, your hands are undeniably sensitive, but why do paper cuts hurt more than cuts from other objects, like knives? Well, even a dull knife usually has a sharper, straighter edge compared to the flexible, rough edge of a piece of paper. When a knife cuts, it tends to make a cleaner incision, whereas paper bends slightly, causing microscopic damage to the skin. Additionally, paper cuts are typically more superficial than most other injuries. A shallow cut might bleed little, if at all, and without a blood clot to shield them, the nerves around the cut are exposed to air and other irritants, making the pain more intense and prolonged.
