"You have to take some time out to be able to give literature the attention it deserves -- for journalism, for speaking, for friendship. I cannot be cloistered like a monk because I would lose contact with human beings, with life," the versatile Fuentes told AFP in a 2003 interview.
A leading figure in the 1960s Latin American boom in Spanish-language literature, Fuentes befriended both Colombian leftist Gabriel Garcia Marquez and Peruvian conservative Mario Vargas Llosa, and was known for criticizing both the harsh side of capitalism and the tough realities of communism.
Unlike his contemporaries though, Fuentes never won a Nobel Prize in literature, although for years he was mentioned as being on the short list and collected a clutch of other prestigious awards.
"I met him 50 years ago," Vargas Llosa said in a Twitter message upon learning of Fuentes' death, "and we were friends all that time without anything ever impoverishing that friendship."
Fuentes' travels helped shape his leftist political views and fueled his passion for political activism.
Like many Latin American intellectuals of his era, for years he was fascinated by the Cuban revolution and by leftist rebel movements. But over time, his opinions grew more nuanced.
"Cuba is worthy of condemnation, and so is the United States," he was quoted as saying.
Fuentes published his first collection of short stories, "Masked Days," under the guidance of his father Rafael.
At the age of 30 he achieved international renown with his 1958 book "The Most Transparent Region," a portrayal of Mexico City which was experiencing explosive growth.
At the time, Mexico City was, in literary terms, "just an orange falling off a tree... all I did was eat it," Fuentes said in 2003.
He followed up with "Good Consciences" (1959), "Aura" (1962) and then "The Death of Artemio Cruz" (1967), which won both critical and public acclaim and became his best known work.
On the linguistic front, Fuentes also aimed to be on the cutting edge.
It is imperative "to break the mold of this dusty old heavy academic Spanish and give it new life, slap it in the face, inject some semen into it," Fuentes wrote.
Taking a turn as a diplomat, in his father's footsteps, Fuentes agreed to be Mexico's ambassador to Paris in the early 1970s.
Not long afterwards he scored a new literary success with "Terra Nostra," a novel on the complex cultural issues of the Iberian and Latin American worlds for which he was awarded the prestigious Romulo Gallegos prize in 1982.
Other leading prizes were not far behind -- from the Cervantes (1987), to the Ruben Dario and Prince of Asturias (1994).
His 1985 novel "Old Gringo," about the disappearance of US writer Ambrose Bierce during the Mexican Revolution, was a best seller in the United States and was made into a 1989 movie starring Gregory Peck and Jane Fonda.
Fuentes' 1987 "Cristobal Nonato" examined the then-upcoming 500th anniversary in 1992 of the arrival of the Spanish in the Americas.
His intellectual curiosity led him down other paths to the 2002 "This I Believe," on his personal ideological and literary beliefs.
In 2003, "The Eagle's Chair" imagined the outlines of Mexico's future, and the following year he published "Against Bush" -- casting his ballot against the US president's reelection that year.
Fuentes supported the election of conservative president Vicente Fox in 2000, which ended the seven-decade rule of Mexico's Institutional Revolutionary Party (PRI).
"In the Americas we sometimes don't realize democracy takes a long time to cook, maybe because we are used to abrupt decisions and heavy blows typical of dictatorships," he said in 2001.
The late author is survived by his second wife, journalist Silvia Lemus, and a daughter from his first marriage to the late actress Rita Macedo. His two children from his marriage with Lemus, a son and a daughter, both died before him.
"He was very enthusiastic and very generous," recalled Mexican author Xavier Velasco in an interview on the Milenio TV network.
Velasco, who said he had dinner with him just days ago, said: "I firmly believe that he is the greatest novelist Mexico has ever produced and also the one with the best sense of humor."