You relax the tight grip you hold on your consciousness and the voice that is you in your own mind and... and actually that's kind of it for 'you'. It's now 'you', plural. Unfortunately, in English, it's the same pronoun, so it's not very dramatic written out, but you're now every mushroom that ever was, is, and ever will be. You are every life forms that has died and all the thoughts they took with them. You are the afterlife of everything. As all living things die, they slowly become more you.