Nguyen Cao Ky once flew a helicopter into the courtyard of his girlfriend's house to impress her, causing havoc in a otherwise peaceful village.
On another occasion he was said to have pointed his shotgun at a reporter because the man's questions annoyed him.
Some members of his own government loathed him and the public nicknamed him 'Cowboy'.
But the Nguyen Cao Ky who arrived in Ho Chi Minh City on Wednesday after nearly 30 years in exile is a different man.
Nguyen Cao Ky was known to be flamboyant and mercurial
His views on the Vietnam War, when Mr Ky fought as a pilot and air commander for the defeated South, have changed too.
"That war was instigated by foreigners, it was brothers killing each other under the arrangements by foreign countries," he told the BBC shortly before he travelled back.
"In another 100 years, the Vietnamese will look back at the war and feel shameful. We should not dwell on it as it will not do any good for Vietnam's future. My main concern at the moment is Vietnam's position on the world map," he said.
Mr Ky said he was returning to Vietnam after being invited by "brothers and friends", and that his message was one of "harmony and reconciliation".
Those were not words General Ky used when in power, as prime minister and then vice president of South Vietnam.
Famous for his aggressive anti-communist statements, he vowed to fight until his last breath.
Perhaps for that reason, his decisions to flee Vietnam in April 1975, and to return now, have provoked much anger from some Vietnamese expatriates and former South Vietnamese soldiers.
"He should not go back. He has betrayed all of us," said a veteran now residing in San Jose, California.
Asked about this, Mr Ky insisted he did not want to discuss the war and hatred anymore.
"Those who bear grudges only care about themselves. I'm an old man now, so I have decided to dedicate to my country all that I have left to contribute - my mind, my health, my wisdom. I just want to help.
"I don't hold a Vietnamese passport but I'm a Vietnamese citizen, no less. What else can I be?" he said.
Bui Van Tung, a colonel in the Communist army, told the BBC that he respected Mr Ky's desire to return to visit and he hoped the former general would be welcomed.
But for many Vietnamese living inside the country, the memory of the war is still painful.
The People's Police newspaper wrote last week that Mr Ky had committed serious crimes in the past, and the Vietnam Net quoted a top official saying he had made "grave mistakes" during his time in power.
Mr Ky's goodwill statements are perceived by some as false promises.
Bui Duy Bao, an office employee in his 30s from Ho Chi Minh City, said he thought Mr Ky was only "boasting about his commitment" to help Vietnam and that he was "no different from other Vietnamese overseas who return at Tet (the Lunar New Year).
"He'd better give away some of his money to the people who need it," he said.