When I first started learning Photoshop as a teenager I often knew what I wanted my final image to look like, but no matter how hard I tried I could never get the there. It wasn't that it was impossible, it was just that my skills just weren't there yet. I needed a lot more practice before I got good enough to create what I could see in my imagination.

Sora is obviously not Photoshop, but given that you can write basically anything you can think of I reckon it's going to take a long time to get good at expressing your vision in words that a model like Sora will understand.