Oh, I know just what you mean! Here, someone took a picture of me just at the moment when I felt it most intensely.

That's me right there on the ocean or some bay or whatever in Sarasota. Or maybe I was round the back side and out of frame entirely. Hard to tell w/ all the cloud cover. But this picture captures exactly what I felt at that moment. It was terrifying! I had the sense that I actually didn't exist and an intense, irrational fear that I might just lose gravity (or gravity lose me) and float off into space, away from air and water and all sustanance.
I'm only being a tiny bit facetious here. I had gotten out, was just over 18. I had a job and a place to stay, knew I could pay my share, finally had actual days off to fill. One problem, though, I had no fucking clue what I might want to do with time and freedom. I knew, factually, that I needed clothes. Maybe I should go to a maul (yech!) and shop like normal 18yo girls do. But I didn't know what kind of clothing I liked.
Didn't even know where to begin. So I remembered that I used to like going to the beach. It always had seemed to help me regain my calm, my focus, my inner peace and all that intangible shit you never even notice in inventory till some asshole manages to pilfer the stores of it.
So there I was on my day off, sitting at the point of a pile of large boulders on the edge of the Gulf which connected w/ the sea which abutted the land... all of it. And I was so incredibly alone. I didn't even have myself. As I sat there trying to remember how to think, trying very desperately to find 'myself' I realized I was completely lost. I had no opinions, no preferences, no friends, no clear memories--every one I could conjure was tainted or completely obscured by the Program filter through which I had become accustomed to seeing everything I allowed myself to see--no volition, no will, no fucking idea what I wanted to do now that I could do anything. It was like walking off a cliff into .... nothing, nothing at all, void.
I finally, after a couple of months, it seemed like the dogs were finally off my trail and I had achieved that long and hard fought goal of having time and space to think and the freedom to do whatever I wanted to do.
So I decided I needed most desperately to job my memory. I went back home to Pompano. Another little lucky break for me; my mom had sold the family home and built herself a new one in Sarasota to be closer to Straight. The rest of the family had already fled to other areas just about as soon as they could. So I had Pompano all to myself.
It helped, sort of. It's true, ya can't go home again. But the familiar, if altered, surroundings did provide me w/ some context to latch onto.
I still don't know who I am. But I don't think anybody does. I don't think it's up to us to make that determination. It's entirely up to the rest of the world to define us as they will.
You say there is but one way to worship the Great Spirit. If there is but one religion, why do you white people differ so much about it?
--Chief Red Jacket, Seneca Indian Chieftain