Jake Rogers, 22, still had cannabis in his system from the night before when he crashed head-on into Dr Alex Boorman, who was driving to work in York along the A19 near Easington, North Yorkshire.
The horrific crash which also badly injured his two passengers happened only two months after his latest speeding offence, and Rogers had 10 points on his licence at the time, Teesside Crown Court heard.
One witness on the road that night in December 2017 told police Rogers was driving like an “idiot”, and the teenage girl who was in the back of his Vauxhall Viva pleaded with him to slow down on their way back to his house in Thirsk from a trip to Burger King, the court heard.
His speedometer stuck at 87mph after the crash which happened in a 60mph zone on a sweeping bend on an unlit section of road.
Other drivers had seen Rogers’ car overtaking dangerously before the smash and it was estimated the period of criminal driving lasted for one and a half miles, the court heard.
One witness said his Vauxhall Viva was so close behind her she could not see his headlights in her mirror moments before Rogers tried to pass her Range Rover, but hit Dr Boorman’s Suzuki instead.
Heather Gilmore, prosecuting, said: “She (the witness) described hearing a massive bang, she saw a massive fireball flash and black smoke and saw the motorbike flying around in the air.”
His car flipped over three times and landed on its wheels, and Rogers was later heard to say: “Oh my God, what have I done?”
His female passenger broke her back and now finds walking and exercise painful, while the friend in the front seat suffered a badly broken leg and was flown to the Leeds General Infirmary.
Rogers admitted causing death by dangerous driving, two counts of causing serious injury by dangerous driving and driving while over the limit for cannabis.
He told police he smoked cannabis every night and had up to three joints the night before the crash.
Rogers wept in the dock as Judge Simon Bourne-Arton QC told him: “Alex Boorman was 27 years old when he died.
“When you killed him, he left behind a loving and devoted family and partner.
“He was a doctor, he devoted his life to that job, that profession. He devoted his life to the care of others.
“He spent many years of hard work achieving that ambition. That career was taken from him by you.”
Dr Boorman’s mother Liz Cinnamon read a moving statement to the court, describing her family’s devastating loss.
She said: “He was a bright lad, a complex character, hugely talented, scarily intelligent, fiercely loyal.
“He was funny and irreverent, challenging and questioning always, he had an insatiable thirst for knowledge.”
She said his life was “so needlessly taken and wasted”.
The junior doctor worked in orthopaedics, lived in Thirsk with his partner, and planned to helped out in a rural hospital in South Africa.
He had been heading in early ahead of his night shift when he was killed.
Rogers wrote a letter to the judge to express his remorse and shame, apologising to the doctor’s family and to his own.
He said: “I put so many lives in danger because of my idiotic driving that night.
“My actions were unforgivable and like the poor family I have destroyed, I will have to live with this for the rest of my life.”
The judge said he will be banned from driving for four years once he is released from prison.