Bitcoin is the most difficult property that the human race possesses or has yet invented to confiscate—and that's by virtue of the fact that you could take possession of it via your private key. So, if you got your 12 seed phrases in your head, then that would be the highest form of property, because I literally have to crack your head open and read your mind to take it. It doesn't mean I couldn't extract it from you under duress, but it means that it's harder than every other thing you might own. In fact, it's exponentially harder.