10,000 hours by age 21 10,000 hours by age 21 according to author and game designer Jane McGonigal 10,000 hours by age 21 for people 10,000 hours by age 21 this play videogames online good according to author and game designer Jane McGonigal racked up 10,000 hours of gaming inherently successful happy people according to author and game designer Jane McGonigal continues to increase 10,000 hours by age 21