Inaki Garcia Arrizabalaga was 19 when a breakaway commando of the Basque separatist group ETA murdered his father, plunging him into a "spiral of hate" before he changed his outlook and started working for peace in his homeland.
More than 36 years later, ETA says it has finally laid down its arms, but for the business professor at Deusto University in the Basque Country, the highly-mediatised event is but an "anecdote."
For him, the truly key event was on October 20, 2011, when the armed group that killed 829 people in its four-decade campaign for Basque independence declared a ceasefire.
"It was inevitable that they were going to hand over weapons," he said this week ahead of Saturday's official disarmament ceremony in Bayonne in the French Basque Country.
Sitting in his office in Spain's northern Basque seaside city of San Sebastian, the 55-year-old calmly remembered the day his father was found shot dead, his covered corpse propped up and chained against a tree.
"On October 23, 1980, I was a student at this university, I was in class and at 8.30 in the morning my older sister came to get me, and said 'come home, dad didn't show up at work'," he said.
"All of us siblings went home, we started asking around in hospitals to see if there had been an accident, and no."
Then came a call that a body had been found on a hill in the city.
They all went and discovered it was their father's, a director at telecoms firm Telefonica whom he later found out had been targeted by the Autonomous Anticapitalist Commandos, an anarchist breakaway of ETA, in retaliation for phone taps being used against militants.
Ensued four, difficult years during which he plunged into what he calls a "spiral of hate," before being sent to London to study by his mother.
Away from the strife, he was able to think more clearly and came back a changed man, he said, realising the killers had not only murdered his father, but were ruining his life as well.
Later, he started working for peace and conciliation and has never stopped, giving talks about his experience in schools -- among other initiatives.
In October 2011 when ETA declared a ceasefire, Garcia Arrizabalaga was giving a presentation at a conference.
"In the Q&A session, a woman from the audience spoke -- she knew my experience and personal story -- and said 'Inaki, I want you to know and everyone to know that ETA has just announced a permanent ceasefire'," he said.
"Everyone stood up and started to applaud".
"My first thought was for the people who weren't with us anymore -- my father, all the victims I knew... so much pain, how much suffering could have been avoided," he said.
With peace having returned and as he looks to the future, one of Garcia Arrizabalaga's chief concerns is that the youth of today are already forgetting what happened such a short time ago.
"If we act as if nothing happened, if we don't learn a lesson out of all of this, we run the risk that it will happen again," he warned.