How much control do you want?
That much control is enough that your friend has an accident, bleeding in front of you, and you have full control over yourself to think positive that he will not die, so there is no need to take him to the hospital?
Or you have a great loss in business and you have complete control to think positive over ignoring the situation, not analyzing the loss and not worrying about the future.
First, you need to change your thinking to think positive. Rather than learning control over yourself to think positive, control yourself not to think anything else but what is preferred in that situation.
If there has been an accident with your friend then there is a need to think negative, so that you can take positive action.
If you had a loss then you need to think negative and take the measure which will lead to a positive future.
