Thinking positively means that you turn a blind eye to the endless potential negative outcomes and stay focused on the outcome you want as something that you are capable of achieving. Notice how this is different that turning a blind eye to the challenges that could potentially create those negative outcomes. Those challenges need to be taken into consideration and mitigated to the point where they do not stop you from achieving the goal. Those challenges are real and will not simply go away. But just because they exist does not mean that you cannot overcome them or work with them.