You do not almost die from psilocybin shrooms (definatly not from most common psilocybe and copelandia sorts). Especially not in the common doses. Also its pretty damn hard to overdose on psilocybin. In the worst caze you'll feel sick from it. There's ego death though, thats when you kind of forget who you are. Its only on really high dose (I for example couldn't tell when I looked at my hand where it ended and the world started, it was on hawaiians. I love hawaiians). Either way if you don't eat a poisonous one or more then 100 caps in a row, or half your body weight of them, you won't die from it.