You could do anything. For example if you were playing football/soccer you would know exactly how hard and at what angle you would need to strike the ball in order for it to be a goal, so you could score 100 times in each game and be the world's best pros. Or if you ran for President, firstly you would know all the right things to say and do and the right person to say them to in order to get nominated and then what things to say to the nation to convince enough of them to vote for you. You'd also know some awesome things - is there a god, is there intelligent life out there, the cure for cancer, the meaning of life!