Sure, you don’t actually own it. The words you strung together are not actually yours nor is the grammar you strung it together with. The knowledge you used to create it is also not yours.

The only way to ensure no one reads, borrows, or “steals” your work is to never share it with anyone and certainly never put it on the Internet.

The only way to ensure it is truly yours is to never have participated in society, invent your own language, and of course hide it from ever being discovered.

This is the only real way. You need to create in a vacuum and lock it up so no one will ever find it. Then and only then can it truly be yours.