He has said that he will not serve a third, yes, a third, term as Prime Minister. That means he presumes he will be getting a second term. There is nothing wrong with having a dream, but how many terms he gets is not in his hands. His perceived arrogance in thinking that he could get a third term might work against him.
He has also presumed to tell us who will lead the Tories once he retires. That will be Theresa May.... or Osborne or Johnson. Now I have no particular worries one way or the other with May, but I do not want Osborne and Johnson's loud mouthed clown act does not fool me. He is ruthless and dangerous and I do not trust him an inch. With a bit of luck Cameron's endorsement of them will critically damage their leadership aspirations. Tory MPs might well disagree with him.