You're an angel.

It's called vertigo

In the hospital under chemo almost halleucinating. I think it means they gave me a shitload of drugs.

Perhaps you are strongly psychic and was feeling the beginning of astral projection. I've done than a number of times, but usually when lying down.

@Meililiken

That's neurosis. It's linked to B-vitamin intake, water, stimulation habits, sleep cycle habits and macronutrients.

low blood pressure

I drank a lot of rum once and this happened.

It means you are falling grab something quick.

lol i used 2 do this all the time...it meant i was about 2 pass out because my blood sugar was low

Vertigo..? If I’ve something to hold on to, something super solid - and I’m standing somewhere high up to begin with - looking up at anything even higher can/ will make my knees buckle

In my case, vertigo. I am terrible with height, looking up is very bad, down is far worse.

Flashbacks?

Out of body experiences? Nope.

No, I have never felt that.

So far, all of the religious responses, as well as the negative health responses have been erroneous.

When it happens, I get no negative effects. At least beyond my direct physical body. But the euphoric feeling can feel so good that I have to struggle with myself not to get lost in it. I become unaware of my direct surroundings, but I start seeing images and equations overlayed of seeing the area all around almost like a bird's eye view, though not a single location, but everywhere at once.
The only true negative is if I'm driving, I could lose myself in it, and crash. I never feel dizziness either.

You have great posture.

Vertigo see a Dr

I used to have those feelings regularly in semi-dream states. They happened all the time when I was in my 20s and 30s, very rarely any more. I was always prone lying in bed but not in a full sleep state, floating and moving above hills or forests, water, cities, lots of things. They were wonderful feelings! No drugs BTW, just simply falling asleep. Not frightening or weird, just euphoric. I miss them but can't get them back through trying. Much like life itself.