TORONTO -- Andre De Grasse is on a break between classes at the University of Southern California, and for once he has nowhere to be.

There are no track practices or lifting sessions for the 21-year-old, who hasn't run down the track since his stunning Olympic debut at the Rio Games. It's all about the books as he finishes his sociology degree -- fulfilling a promise he made to his mom Beverley.

"I made a promise to her and a lot of people, even here at USC, that I would come back and finish what I started because I didn't want to leave that chapter of my life behind," De Grasse said after class, from Los Angeles. "I enjoyed my time here at USC so much, and a lot of people see me here putting in a lot of work and effort, and I didn't want to let that go to waste, and I thought this would be the perfect time now that the Olympics are over."

De Grasse captured a silver and two bronze medals in Rio after opting out of his final season of NCAA eligibility at USC to turn pro.

He'll finish his degree in December, and then move back to Phoenix where he trains with Altis, home to 100 or so of the world's top track and field athletes.

The plan was to take two months off after Rio, and he's kept active playing pickup basketball or soccer with friends. He's hammering out a plan with coach Stu McMillan to perhaps travel to Phoenix on weekends until he's finished his schoolwork.

"It's been going by pretty fast, I can't believe it's the end of October already," he said. "Only a month left and then exams. I thought it was going to be a little bit stressful, coming back after the Olympics, but time has actually been going by pretty fast."

De Grasse's career has skyrocketed since he left the USC campus last winter, but his college friends were quick to bring him back down to earth.

"A lot of people joke around because they knew me before that happened, so they're always trying to tell me 'Hey, don't get too big-headed now, we knew you before all that happened,"' De Grasse said, laughing. "They keep me humble."

He's posed for plenty of pictures though, and has done some Q&As and student-athlete panels at the request of his professors.

The Markham, Ont., native was one of Canada's most captivating storylines of the Rio Olympics, his relationship with Jamaican superstar Usain Bolt painting some unforgettable pictures.

Bolt will race at next summer's world championships in London in what's being billed as his "farewell" meet. De Grasse can't wait for another shot at the 29-year-old.

"If it is going to be his last time, I've got to just try to enjoy the moment and have fun and go out there and give it my all against him one last time," De Grasse said. "It's going to be interesting to see where I'm at next year, and see where he's at."

As far as unseating the world's greatest sprinter, however, De Grasse is measuring his words. The young runner said his confidence has sometimes been misinterpreted.

"I've noticed that in the past year, people tell me about interviews I do, and they say 'They make you sound like you're cocky but you're not really a cocky guy,"' De Grasse said. "I don't want to rub people the wrong way where I sound cocky and say I'm going to beat Bolt. At the same time, I'm confident I can go out there and compete with him, and beat him."

Besides his studies, De Grasse is working on developing his own charitable foundation, saying "That's pretty important for me, because I want to give back to the community."

He'll travel to Chile with Puma -- the company with which he signed his historic US$11.25 million shoe deal last winter -- on Oct. 27. There are also early plans for a "street meet" this coming summer that would see him race in downtown Toronto.