My father loves telling the following story:
One day him and my mom were picking mushrooms. An American family (we're originally from russia, though now proud US citizens) saw them walking in and out of the woods, and asked what they were doing. They told them that they were picking mushrooms. Sometime later, my father watches the father walking with his family of wife + 2 kids carrying what he calls "the largest, most poisonous mushroom he'd ever seen". The guy was beaming at his "amazing haul". My father had to walk over and tell the guy to put the mushroom down, and get to the nearest bathroom without touching anything, especially not his children.
I use this story as a warning to anyone planning on picking shrooms without a good primer/teacher.