Before starting his gold quest, Phelps has also learnt to play coy game and talked down his ambition.
"You guys are the ones who talked about it. I haven't said anything about breaking any records," he told reporters a week ago, referring to the goal to eclipse Spitz's mark of seven golds at a single Olympics.
"My goals have never been published. Bob and I are the only two persons who know (the goal), and we are going to work through this week and the next to accomplish that goal," he said.
But when Phelps hit water, you knew that he had the target in mind. He has won five races so far, all with new world records. When teammate Jason Lezak secured the gold of 4X100 free relay, he belched out screams and went overly emotional.
The established Olympian clearly knows the weight of his achievements. "When you win an Olympic gold medal, it stays with you forever," he said, "Birthdays happen every year, Christmas happens every year, but the Olympic gold medal definitely never never gets old."
Five days in Beijing, Phelps was the reason to keep fans stay up late to watch his races. "My friends said the people in the US have gone crazy... It's pretty cool to have a country behind you and on your side," he said.
And in Beijing, Phelps inspires as his legend continues.
"Phelps is the only swimmer in the world I know of," said Chen Xinrong, a 12-year-old Beijing student who watched Phelps' race with awe. "Look at his arms! He is so strong and every time he swims, he gets faster. I wish I could be like him."
The greatest Olympian is still on the way to become greater. He is aiming at three more golds in the rest of the races.
"It's not over yet, anything can happen in the next three events," Phelps said, knowing the gold could change hands in a split of a second.
"I'm not unbeatable. No one is unbeatable, everyone can be beaten," he said.