Someone correct me if I'm wrong... but I think some mushrooms like false morels have toxins that accumulate in your body and eventually do organ damage, similar to the way mercury accumulates in the body.I've eaten a lot of these, meaty with a great morel flavor. I only eat a few at a time.
Some books call it poisonous, some say edible.
The false morel, brain morel, snowbank morel. Gyromitra whatever. Common in the Uintas, has dangerous lookalikes.
Wear gloves, cut the mushroom in half and look for chambers, consult your field guide. Do not eat any false morel raw.
Be careful out there.
I've never wanted to eat those, even though I may be able to eat a few without getting sick.