You are the sort who die every year in the north western states. Mushroom toxin can be deadly in very small amounts - so the answer is VERY. Know your mushrooms and know your region before you start dancing from field to field with a basket and an itch for a free high. If your mushroom stains indigo and leaves a purple sporeprint and you are in north America then you are most likely ok. But don't take the word of some clown typing to you in a marijuana growing forum - it is your liver and your life you are putting on the line for a buzz. Take care also - people who know what they are doing have been known to be careless in their picking. There are a few species that in a particular stage, look just like your target mushroom. People have been known to accidentaly put them in with the other "good" ones to very bad effect. Get a good regional key, find some knowlegable foragers in your area, join a foraging group, keep quiet and learn.