Pain is a complicated thing. To make life easier, let’s not consider abstract pain, like the pain of watching the latest Star Wars movies. Instead, let’s focus on a specific kind of pain — getting your finger hit with a hammer.
So, after a hammer hits your finger, a lot of stuff happens. Hard to believe, because it happens very fast.
It all starts with the pain being turned into an electrical signal in the finger that got whacked by the hammer.
After that, the signal is sent to the spinal cord, which passes it along and, along the way, decides to yank the hand back just in case. This happens even before we notice that it hurts.
Then the pain signal slowly reaches the brain, and we start to notice that it hurts. That’s when the screaming begins.