Your description of the "three ways" is very clear. Your second way sounds like when I've worked diligently at a problem, maybe for months or years, and have finally seen past it, or into it, enough to "get it." It's like a burden has been lifted, so I'm freed from some excess baggage I didn't really need.
I like the plastic metaphor. I often say that it feels like there's a layer of Saran Wrap between me and the world, and it feels like I'm the one who keeps the plastic layer in place. Like if I let the world get "too real" I won't be able to handle it. Fear, maybe, but of what?
Then, on a good day, it's like the plastic gets peeled away, and amazingly it's not fearful at all. It's exhilarating. Alive. Vivid. Real.
One way I can peel back the plastic is when I'm really into taking photographs. When the plastic goes away, I see everything around me as photographic compositions. They're everywhere, and they're so clear they almost vibrate. That doesn't happen often but when it does it's like being in an alternate universe.
I suspect that there are an infinite number of ways of suddenly finding yourself immersed in hyper-vivid reality. Deep meditation. Artistic exploration. Music.
Maybe ANYTHING that let's you lose yourself, forget your fear, and tune into to unexpected layers of reality you didn't know existed. I think maybe what you've described from your own experience is a very deep drop into what you didn't already know.