The winger has been thrown into a struggling Red Devils side in his debut Premier League season, with manager David Moyes often preferring him to more experienced players such as Ashley Young and Nani.
Januzaj, 18, has thanked Moyes for showing faith in him, and has vowed not to let the success that he is enjoying at a young age distract him from his target of being one of the best players in the world.
"In football it's not [about] age. If you're good enough to play, you have to play," he told MUTV.
"I think the boss gave me the chance because he's known for giving a chance to young players. He's a top manager and knows exactly what he is doing with the players and everything else.
"You always have to keep going and work hard if you want to be even better. My parents always told me to keep my feet on the ground, keep working and, if you can, try to be the best player in the world."
Januzaj has made 13 United appearances in total since debuting in the Community Shield in August.