I think you misunderstand ownership. Bitcoin is the ONLY thing you can truly own.
You can memorize the private keys and nobody can take it away from you.
Discussion
Uhm.. ok I see your point but..
Imagine in 10 years chips implementation and some strange technology or nano bot inoculated in a drug or vaccine get in your body somehow.. and they can start read your thoughts. You can think like an absurd idea bit it is much more real than what many believes.. many companies are investing millions on this already.. mind maybe will not be that safe in the future.
Other example.. hypnosis. Some get out the info and you even know.
Property for me is many times something that others, the State primarily, recognize of your belongings. Bitcoin has no State.