When I was a kid, I thought two things were going to be much bigger problems in my life than they actually are - quicksand and mad cow disease. Turns out that they aren't but mad cow disease is still the stuff of science-fiction nightmares. Mad cow disease is caused by the spread of prions, proteins that weaponize our own cells against us and cause proteins to misfold and aggregate, slowly killing neurons throughout the brain. The disease is characterized by rapid and fatal neurodegeneration....