Usain Bolt of Jamaica applauds fans during a lap of honor at World Athletics Championships at London Stadium August 13, 2017.[Photo/Agencies]

"What we're going to miss about Usain Bolt isn't the three back-to-back Olympic Games or the clutch of world records and medals," said Sebastian Coe, the leader of track's governing body, the IAAF. "It's because he has an opinion. He has a view.

He fills a room. We have terrific talent that's identifying itself at these championships. But that's not the same as filling that void, and we have to work at that."Bolt's standing-room-only news conference was scheduled for 15 minutes but went about 35. He discussed his past, the future and the sport he leaves behind.

He said over the long term, he could see himself coaching track and occasionally stepping into the TV booth for the sport's biggest events. His immediate plans? "I need to go out and have a drink," he said.

Asked one more time about doping, he said he thinks track is on an upward trajectory after two dispiriting years involving a doping scandal in Russia and problems across Africa and in his own country, Jamaica.

"I've proven to the world that you can do it, that you can be great without doping," he said. "Hopefully young athletes can look at me."As far as a comeback is concerned, he insists it simply won't happen.

"I've seen too many people retire and come back and make it worse and shame themselves," he said. "I personally feel I won't be one of those people."But he has no regrets about running in this meet, or concerns that the results will tarnish his legacy. In a way, he said, the jaw-dropping losses were similar to the breathtaking wins: They showed that when he's on the track, anything really is possible.

"For me, it was brilliant," he said of the week that was. "I'm just really sad I have to walk away now."