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.

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.

You have great posture.

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.

No, I have never felt that.

Out of body experiences? Nope.

Flashbacks?

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

low blood pressure

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

@Meililiken

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

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

It means you are falling grab something quick.

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

I drank a lot of rum once and this happened.

It's called vertigo

You're an angel.