Can we ever say this is mine when talking of a thought, of an idea, of a value?

What would it mean to be able to create privately? Isn’t it what God, if ever there was a God, did or is still doing (continuous hidden creation)? Are we strong enough to create without a signature? Are we strong enough to even create? As soon as I am writing for someone, I might be producing a speech ‘in inverted commas’, a simulacrum of subjectivity.