Ian Goldsack, prosecuting, told the court Wan, who had moved to the UK from Hong Kong and bought his Mazda car not long before the collision, had considered himself an inexperienced driver.
Mr Goldsack said the defendant maintained he had been complying with the 40mph speed limit but lost control of his car while navigating a bend in the road.
While a collision investigation report could not establish the speed of the car, it concluded it should have been possible to drive along the bend safely even at speeds of up to 60mph.
The Recorder of Sheffield, Judge Jeremy Richardson KC, said even if Wan had been travelling above the speed limit, it would not have been “a widely excessive speed” and between 30-40mph.
Judge Richardson said speed had not been “the real issue” but rather Wan’s “complete inattention and a comprehensive loss of concentration”.
Passing sentence, he told him: “Your very bad driving took the life of a decent man, who had a whole life ahead of him with his wife who had that very day retired from work.
“You have wrecked her life.”
Christopher Aspinall, mitigating, said the events of that day had “haunted” his client, who wished to extend “an unreserved apology” to Mr Bower’s family.