If I understand you, you're trying to grasp something that no one really has and could never be proven, but you have past lives memories of. If you're REALLY one of the magical beings that belonged in the Magical World whom happened to incarnate as a human, life is tough because you're new to the human body, so you have mental certain incapabilities and meanwhile you lost certain magickal capabilities that would help you in our world. In any case, stop trying. You should start by loving yourself, then your vibration will raise high enough for human psychic awareness in this world.
You will never really come back to the top of mushrooms with elves (thanks to Cliff for that info), enter red trees, or go on the surface of crystals. First those creatures are in another density and they're also much smaller in scale. And second they only show up in our world through traumatic events (such as red trees getting chopped off. there was this one event when people saw small elves marched across from a redtree that got chopped).
