With the bit of intelligence which remains in your brain, you decide to become 18-years-old again, keeping all the other changes. You immedialy grow to seven feet and two inches tall, becoming incredibly muscular; your clothes turn into a tight shirt, shorts and sandals.
You fighting skills increase, too: you now are highly trained in Karate, Judo, Tae Kwon DO, Kung Fu, Thai Boxe and Kick Boxing, besides you're the captain of the Wrestling Team of your school. You're very dumb but basically a nice guy.
On the screen, you read: "ENJOY YOUR CHANGES! REALITY HAS CHANGED, TOO, AND MEMORIES OF OTHER PEOPLE HAVE BEEN PROPERLY MODIFIED, SO THAT EVERYONE'S GOING TO CONSIDER AS NORMAL THE NEW SITUATION. THE CHANGES ARE GOING TO LAST EXACTLY 72 HOURS FROM NOW, THEN EVERYTHING WILL AUTOMATICALLY REVERSE TO NORMAL".
"Good!" you think. "I've three days of fun." And you go to...