On a clear night with good stars, lie down on your back and look up at the sky. Wait until you can start to recognize that those stars are out there at a depth and that you’re looking through an intermediary space between your location and theirs.
Once that is tangible, now try to adjust your perception such that you feel as if you’re looking out, not up: Pretend that you are strapped onto the front of a giant object - like a mermaid on the front of a wooden ship. See the stars as a field in front of you, with the lower part of your visual field (toward your feet) as below you and the upper part of your visual field as above you such that if the straps were cut you would slide down the front of this surface into an abyss below your feet.
If you can get it right, it has extraordinary consequences for your perception of your orientation in space. If you happen to live somewhat near the equator and have in mind the standard visual orientation of maps and globes, you might even think that this is a more correct way to see your position - that “up” is actually “out”.