"He has matured a lot," said his American rival, Wallace Spearmon. "The antics have been turned down a little bit."
"First time I saw Bolt, he was playing tag with some little girls 10 minutes before our race," Spearmon said.
On Thursday, in a shade under 20 seconds, Bolt will win the 200 meters and crown himself a legend. Or he will lose, in what would be one of the most significant upsets in Olympic history.
While his rivals have plotted how to shave every last hundredth of a second off their time, Bolt has campaigned for a tryout with Manchester United.
Not that it mattered. Bolt said he worked hard for "the first 70 meters" of Wednesday's 200-meter semifinal, then let up. He still won his heat, even with the fifth-fastest qualifying time for Thursday's finals.
"It is all about going through as easy as possible," Bolt said.
Bolt was one of three Jamaicans qualifying for the eight-man finals. Yohan Blake of Jamaica had the fastest qualifying time at 20.01 seconds, followed by Spearmon in 20.02 and France's Christophe Lemaitre at 20.03.
Spearmon, the lone American in the field, bristled at the suggestion that Bolt and Blake had all but wrapped up the first two spots.
"That's why we're racing," Spearmon said. "If we weren't, they'd just hand them the medals and we'd race for third or whatever."
Bolt's time Wednesday was 20.18. But the world record of 19.19 belongs to him, and so does the Olympic record of 19.30.
He is trying to become the first man to win back-to-back gold medals in the 100, 200 and 400 relay. He set an Olympic record -- and approached his world record -- in repeating in the 100, despite the murmurs that surfaced when Blake beat him at last year's world championships and this year's Jamaican Olympic trials.
"They are always doubting a champion," Bolt said. "That is why I am here, to cement my legendary status."
Bolt knew exactly when he could shift to a more relaxed gear. Blake did too.
Spearmon, not so much. He ran in the heat with Blake, and he could tell right away that he would not win. Spearmon decelerated, then frantically accelerated, sensing a runner on his shoulder and realizing the top two finishers were the only ones guaranteed spots in the final.
"I had to turn it off and had to turn it right back on," Spearmon said. "I scared myself a little bit."
Spearmon is no favorite in this race, but he is no 100-1 long shot either. In 2005, he was ranked No. 1 in the world in the 200 -- granted, early in Bolt's career -- and the only men in the field with faster personal bests are Bolt and Blake.
That points to bronze for Spearmon, but he can fall back on a little bit of history.
Remember the race in which Bolt played tag with the kids minutes before the start? How did that one turn out?
"I won," Spearmon said.