(Sebastian Kahnert/picture-alliance/dpa/AP Images)

Michael Phelps was the world's greatest swimmer.

Coach Phelps? That's going to be a work in progress.

Now that he's retired from competitive swimming after winning 23 Olympic golds and 28 medals overall, Phelps plans to work as a volunteer assistant for longtime coach Bob Bowman, who runs the Arizona State program.

"It will be a different part for me in sports," Phelps said. "I'll have to learn patience. For me, I always wanted to see somebody pick something up like that. That's what I've done. Bob would say, 'Do X, Y, Z in your stroke,' and I'd say, 'OK.' He'd say, 'No, this needs to change,' and I'd be able to change that little thing. So that might be a struggle for me."

Still, Phelps looks forward to staying involved in swimming by teaching others some of the techniques that made him the most decorated athlete in Olympic history.

"This sport is something that's going to be part of my life forever," he said. "Anything I can do to help somebody accomplish their goals and their dreams, that's why I'm here. Any kid who's hungry enough and willing to work hard enough, that's going to be enjoyable for me."

Then he came back to that ol' patience thing.

"But it's going to be hard for me," the 31-year-old Phelps conceded. "It's going to be very hard. I've definitely got to learn patience _ with college kids especially."