[Tuor Turambar,Cursed by the Valar]

And why do you think he did not know that he had put a lot of his energy into the ring? If he did not know it originally, he would have known it when he lost to the Last Alliance. He would realize that his ring was part of him.

Also- are you insulting Sauron? He was powerful enough to cover the land in darkness, and he almost suceeded again. You cannot say he was not powerful (although you just did)