Au contraire [sp?], Pierre!

Check the USDA nutrition database; mushrooms have significant nutrient value, including protein and minerals. Dried mushrooms rival fresh venison on a pound for pound nutritional basis.

I stick to a very small number of very distinct edible mushrooms: morels, chanterelles, boletes, etcetera. Their combination of size, color, shape, texture, spore tubes versus gills, scent, etcetera are pretiy easy to learn. And I take classes, guided walks, and study the books, just as I do for edible and useful plants. When in doubt, don't harvest or eat the things.

Fungi are abundant during the winter, early, middle, and late, when there are few other plant sources readily available. They cannot run, gradually I am learning where they hide, and often when you find one, you find many. Further, you can mushroom while doing other foraging and hunting, or just traveling. Mushrooming expands your survival opportunities with only a small incremental increase in energy expenditure.

Edit: Today I learned a new mushroom, the garlic mirasmius [sp?]. Distinctive long, dark brown stalk, garlic aroma, and growing habit. Also found button puffballs, an edible. And also a number of poison Amanitas or Death Cap - again with distinctive color, stem, etcetera. Plus many mystery fungi. Again only eat fungi of which you are very sure.