This is not remotely what the "common knowledge" about mushroom foraging is in Eastern Europe. There is a "funny" story in Bulgaria how the most famous mushroom foraging expert in Bulgaria a few decades ago died because he made a mistake when foraging.
Plenty of edible mushrooms are just "twins" of poisonous mushrooms, using animal's knowledge to not eat them, without expending the metabolic cost to actually produce poison.
Plenty of edible mushrooms are just "twins" of poisonous mushrooms, using animal's knowledge to not eat them, without expending the metabolic cost to actually produce poison.