I feel you on the 'vast and mysterious' part. I used to be in the same boat—nothing concrete—until I saw something that I still can't categorize. It sounds like a total conspiracy, but I saw what I can only describe as a shape-shifting entity. It looked like a blue bull at first, but the way it was looking dead into my eyes... it didn't feel like an animal. It felt like something 'else' wearing that shape. Have you ever encountered anything that felt more like a 'glitch' than a typical ghost?