"Growing up as a kid, they called me John and they called me John-John — it really didn't catch on," he said Wednesday. "And then JuJu came into my life and it stuck from there.
"It's a pretty catchy name."
Smith has caught on quickly with the Trojans and is one of several freshmen expected to make immediate contributions when USC opens Aug. 30 against Fresno State.
Smith, receiver Ajene Harris, two-way player Adoree' Jackson, tight end Bryce Dixon and linemen Damien Mama and Toa Lobendahn all worked extensively with the first-team offense on Wednesday night.
“In all three phases of the game, we're going to see freshmen contribute to our success,” Coach
Sarkisian indicated that Harris might be the biggest surprise because he has adapted to receiver so well after playing quarterback at Crenshaw High.
Lobendahn is on track to start at left guard and, with redshirt freshman Kahliel Rodgers questionable for the opener because of a knee sprain, Mama could start at right guard.
"They're both really mature guys," Sarkisian said of the first-year freshmen.
The 6-foot-5 Mama, who played at Bellflower St. John Bosco High, said he has trimmed down from 397 pounds to 377.
"That 20 pounds has helped me a lot," he said, adding that he had difficulty keeping up with teammates during summer workouts. "Now I feel good. They have me doing extra conditioning after practice, which has helped a lot."
Jackson continues to work at cornerback, but his most immediate contributions will come as a receiver and kick returner.
He said he did not have a preference for one position over another.
"I'm just enjoying the whole process getting acclimated to college football," Jackson said. "I'm having a blast and just trying to learn everything to perfect my craft and get better every day."
Jackson, who played at Gardena Serra High, was the Trojans' most high-profile recruit. He said he "wanted to learn everything, not try to come in and act like I've been here before and have done this before. I just wanted to come in and learn and take everything in and get the older guys' trust as well and see where I can go from there."
Smith, who came to USC from Long Beach Poly High, was also expected to get looks on both offense and defense. But he will probably remain on offense because he has been so impressive at receiver.
"I came in not knowing whether I was to play offense or defense," he said. "When Coach [asked] what side I wanted to play on, I chose offense."
Smith, said the biggest adjustment to college football was the tempo of the Trojans' offense.
"It was pretty fast," he said, "and then you start getting used to it and it's good."