The worst pain I ever felt was a couple months ago. A family member was walking the dog, who was on one of those 25 foot extend-a-leash deals. It was summer so I had shorts on.
The dog ran past me and then made a right turn, dragging all 25 feet of that nylon cord tight against the back of my knee. I felt this burning sharp pain so strong I couldn't believe it. I started to scream as loud as I could and then my knees buckled under the pain, which then trapped the nylon cord between my skin and leg all the more making it even worse.
I had a pretty nice brush burn there for several days and could not bear to bend my leg even the slightest bit. It swelled up pretty nicely. It didn't hurt much afterward as long as my leg was straight.
But the pain for the second or two while that nylon cord was burning into the back of my leg was just unreal. I couldn't believe how painful that was because it just doesn't seem like it would hurt that much. I've smashed my face into the road and knocked teeth out in a bicycle accident as a teenager and that pain was nothing compared to this.