Falling. Falling towards a planet, star, or galactic core is all pretty much the same. Tidal forces will be a bit different, but those aren't on a feelable scale with most objects.

OK, but as a poor earthling who's never experienced low gravity... surely the force of gravity affects the feeling of "falling" even if you're not in an orbit around some nearby planet sized thing? Does that feel substantially different than, say, falling down an elevator shaft on earth?

"the feeling of falling" -- That's called weightlessness, free-fall, and zero-gee. Being in interplanetary space, being in earth orbit, being in the parabolic Vomit Comet, being in a drop tower capsule, being in an elevator compartment falling down a shaft, stepping off a diving board, there's no difference in the 'feeling'.

https://en.wikipedia.org/wiki/Drop_tube -- https://en.wikipedia.org/wiki/Reduced-gravity_aircraft -- https://en.wikipedia.org/wiki/Free_fall

In a hypothetical universe that contains only you + space, what would you feel?

If there is no gravitational field, you don't need a fall to cancel it out.

lonely?

:(

If you spent your entire life in an area with gravity prior to that moment, you would feel like you are falling even though you are NOT.

Our brain is used to gravity. That is why weightlessness feels weird.

But falling and weightlessness are indistinguishable to your brain. They are exactly the same thing.

So, if all the gravity around you suddenly disappeared, your brain would initially tell you that you are falling.

Only after some time would you convince yourself that, "No, I'm not falling... Gravity just disappeared. I'm just weightless."

Same thing: falling.

The opposite of falling is accelerating, and you feel acceleration. A rocket rocketing in an empty universe would feel the same as a rocket rocketing in orbit would feel the same as a rocket just sitting around on Earth. Wait, that last one's different...

We happen to live most of lives in a somewhat exceptional case of constant acceleration (with respect to falling). The ground below our feet has gotten us pretty used to acceleration. But, if you jump, you'll feel like falling too!

more accurately, you dont feel falling because the magnitude is so low.

Falling and weightlessness are identical.

Weightlessness only feels weird because we rarely feel it.

If you were suddenly in empty space (e.g. in an area with zero intrinsic acceleration), you would feel like you are falling.

Because the feeling of falling is actually the feeling of NOT having the constant gravity (i.e. acceleration) you're used to.

If you were born in weightlessness, gravity would be the strange feeling (cue Bane saying, "you only adopted weightlessness, I was born in it").