But I did not sell my address in the system. I still own the address.
To say "nothing" cannot be factually correct, because logic dictates that I obviously sold something. I owned "something" that, after the sale, I no longer own. I ask you again, what did I sell?
You asked what you own. You own an address. Like everyone that installed a wallet application. That's all that you own.
I also asked, what did I sell? Obviously, I didn't sell the address, I still own it. But I sold something. What is that?