Feeling itchy from a sunburn, a bug bite or some other skin irritation is miserable, but the pleasure you get from scratching it isn’t just the absence of pain. It feels legitimately good to scratch, and the reason is fascinating. A 2008 study at Wake Forest University hooked people up to a MRI scanner and monitored brain activity when they had their legs scratched at regular intervals. They found that the sensation of having an itch scratched triggered areas of the brain associated with pleasurable memories, while dampening sensation in pain receptors. That encourages you to scratch repeatedly, even though it can damage your skin.