If a person has ra. is it possible that his ra suddenly goes away and the person is back to normal?

Possible but....: What you are referring to is called a "remission" which can be drug induced (I see you are on Enbrel (etanercept) Rx which can result in a medication remission) or a "spontaneous" remission. In "bone fide" cases (in other words, all the criteria for RA are present) then the chances of a "spontaneous" remission is unlikely (but not impossible). Don't stop your Rx ! Ask your MD what type of remission is present