Because most people become overcome with fear, and those not scared to near death are enraged. Few can remain rational in such circumstances.
My closest experience was an enraged 300 lb sow pig which came over the fence while I was castrating her babies. She hit me in the chest and knocked me straight down onto my back. There I was with 300 lb of pig straddling me trying to eat my face and throat.
I very consciously shoved my left arm in her mouth to protect my face. I was wearing a heavy down coat, which got torn to shreds. But I only suffered a few minor scratches before one of the baby pigs came running past and momma pig decided she was more interested in chasing down the baby than in eating me.
This is what college was like for me too.
