Heres some quotes from Wikipedia for you:
The first public mention of Mayo occurred in the Ashland (KY) Daily Independent in an article called 'Phenom' in the paper's January 21, 2001 edition, when Mayo was just a sixth grader. In that article he was listed as being a "6-foot-1½ point guard with size 12 shoe".
Mayo commuted from Huntington to Rose Hill Christian, a private school in Ashland, Ky,since student athletes can play high school varsity sports as seventh-graders in Kentucky. In the seventh grade, his statistics often dwarfed the production of players five years his senior. In his first game for his varsity team he scored 27 points, had seven rebounds and had three steals. He was a seventh grader playing against juniors and seniors in high school.
During his seventh grade year in January 2002, Mayo was mentioned in Sports Illustrated and on CBS Sportsline.com. There were also full articles in The Courier-Journal (Louisville, Kentucky), the Huntington, West Virginia Herald-Dispatch and USA Today.
Thats just middle school.