When Allied forces liberated the Bergen-Belsen concentration camp in 1945, even the horrors of World War II had not prepared the soldiers for what they saw.

"They vomited, they fainted and they cried like children," said Olga Horak, then a prisoner who had survived Auschwitz and the death march to Bergen-Belsen.

"We were already emaciated, skeletal figures. I was 29 kilos. I was together with my mum, who was only 39 years old."

Ms Horak was with her mother the next day when the British gave her a card confirming her registration as a displaced person.

Olga Horak sees talking about the Holocaust as 'a matter of duty'. ( ABC RN: Tiger Webb )

"She held it in her hand and unfortunately she collapsed, and I lost her there and then."

It is stories like Ms Horak's that confound Holocaust deniers, said Professor Colin Tatz, founding director of the Australian Institute for Holocaust and Genocide Studies.

"It's the meticulous detail which has always upset the deniers because the deniers cannot undo the truth of Olga's illness, her weight, the death of her mother."

But as more people with first-hand experience of the Holocaust die, there's a danger these details will fade from the world's collective memory.

'Nobody remembers anything'

US-based organisation Genocide Watch maintains a list of countries where genocide is currently being committed. At the time of writing, it consists of Syria, Mynamar, Sudan, South Sudan, Nigeria, Somalia, Iraq, Yemen and the Central African Republic.

But when it comes to knowing the past, Professor Tatz said for younger generations, "18 weeks ago is history", while 18 years ago is "sort of like the cave era for them".

"You talk about the First World War, they look at you absolutely blankly. They have absolutely no conception," he said.

"We live in an anti-historical or an ahistorical age. Nobody remembers anything, basically, unless they are constantly reminded."

He said human beings have an "extraordinary capacity to obliterate memory" which he suspects is a kind of survival mechanism.

"If you don't have to remember, if you force yourself to forget those episodes, it's possible to go on with life and pretend that there is not only a decent present but there's a decent future."

But could this "wilful amnesia", as Professor Tatz calls it, allow humanity to repeat the atrocities of the past?

Holocaust survivor George Grojnowski said it was unfortunate that people seemed to be forgetting the events of WWII.

"Today we still have a rise of fascism right across [Europe], and that disturbs me as a survivor, that we have it in France, we have it in Poland, we have it in Germany, in Russia, in Romania, in Hungary.

"That's why it is important for us as survivors, as long as we can, that we talk."

Holocaust methods 'invented by the Turks'

There are, however, people who are inspired by the horrors of history, rather than repelled by them.

Hitler was very aware of the Armenian Genocide committed by the Ottoman government during World War I, Professor Tatz said.

An estimated 1.5 million Armenians died as a result of Turkish policies during WWI — about three-quarters of the Armenian population.

"One of the saddest things is that, when we look at the Holocaust and we look at Armenian history, there's very little that the Nazis invented," Professor Tatz said.

He said the "mass factory-like extermination" of people in death camps was, indeed, a Nazi invention.

"But death marches, elementary gas chambers, medical experimentations, rounding up of men, separation of women, special camps, all of this was invented by the Turks, not by the Nazis."

Hitler is said to have referred to the Armenians while addressing his SS officers in 1939, while explaining his plans for what they would do in Poland and Czechoslovakia.

"He outlines the program that Goering had actually alluded to in 1936 when he said, 'We will deal with the Jewish problems one way or another'."

Upon hearing the details of Hitler's plans the SS officers are said to have asked, "How can you possibly do this in the 20th century? The world is watching".

"And Hitler is said to have said, 'Who, after all, remembers the Armenians?'"

Telling stories 'a matter of duty'

George Gronjowski saved his jacket from Buchenwald concentration camp. ( Sydney Jewish Museum: Katherine Griffiths )

Mr Grojnowski was liberated from the Nazis at 18 years of age while on a death march to Theresienstadt, and his striped jacket from Buchenwald concentration camp is held at the Sydney Jewish Museum.

"I thought that I have to have something to remind me of where I was and what happened," he said.

His strongest memory from his time under the Nazis is being transported in a cattle truck to Buchenwald.

"A cattle truck would transport cattle. You don't need any facilities, you don't need any seats and you don't need any toilets.

"So we were pushed in, 100, 120 [of us] into those cattle trucks, completely sealed up and travelling in winter from Poland to Germany."

He also tells how, at his request, a German officer stopped he and his father from being separated.

"I like to tell that story because, in the tragedy that human life didn't have any meaning, there was one human being that had enough humanity that he didn't want to split a father and son.

"Unfortunately four months later my dad couldn't get up … he was gone."

Ms Horak's sister Judith was amongst the first children sent to Auschwitz and murdered. ( ABC RN: Tiger Webb )

Both Mr Grojnowski and Ms Horak were the only members of their families to survive the Holocaust, and both consider it important to tell their stories to a new generation.

"I am not telling my story because I want you to be sorry for me," Mr Grojnowski said.

"I'm telling you a story from a young boy that lost all the family and went through all the horrors of the war."

Ms Horak said she considered it "a matter of duty ... to pass on a message to the generation of today who don't know enough about the Second World War".

"Often, you know, people say maybe it's a good therapy to talk about it. It is not a good therapy at all. It does open up wounds."

While her mother, father and sister did not survive the war, Ms Horak will never say they "died".

"We didn't really 'die', we perished," Ms Horak said.

"I never talk about dying. We were murdered, wilfully eliminated. That was the program."