Sign that your friends don't care about you: They dare you to drink an entire quart of soy sauce.
Sign that you don't care about yourself: You actually do it. (You, in this case, was a 19-year-old living in Virginia, whose case was recounted in the Journal of Emergency Medicine.)
Sign that you've made a horrible mistake: You start twitching, have a seizure, and go into a coma by the time the hospital gives you anti-seizure meds.
Things you don't want doctors to say: "He didn't respond to any of the stimuli that we gave him. He had some clonus, which is just elevated reflexes. It's a sign that basically the nervous system wasn't working very well."
Gross detail you might not want to read: When they put a tube into your nose, brown material gushed out of it.
Why it happened: A quart of soy sauce contains more than a third of a pound of salt, and when that enters your brain, bad things happen. LiveScience can explain more.
Signs you're a lucky son of a sushi: You wake from your coma after three days, and miraculously show no signs of long-term brain damage. (More stupidity stories.)