He was the logical go-to guy, who showed Smith how to get all of the colored sides to match in less than 10 hours of instruction. But if you want to learn just to impress your friends, Mao can teach you in a lot less time.

Typically, he says, "After an hour and a half, (people) can solve the Rubik's Cube with a sheet of instructions on it, without any input from me. After 10 hours, Will Smith was able to solve the Rubik's Cube on his own, without anything. Not only learning the process, but committing it to memory. And Will is a pretty busy guy with many responsibilities. Basically, he had to memorize lines for his scenes and all that other stuff as well."

Initially, Mao was enlisted to help fake Smith's manipulation of the Cube.

"The first thought was that we could get a hand double," Mao says. "It turns out that, first of all, Will Smith didn't want that. It seemed to me he wanted to really just understand the character, so he wanted to learn to solve the Rubik's Cube on his own, and he wanted to do this genuinely on camera.