This Saturday is an important day for Frieda Grayzel.

“January 27 was the day that the Russians liberated Auschwitz, and the day I was restored to life, literally. So I have considered it my rebirth day.” she said. “I include in that all of us who were liberated on that day — starving, sick, emaciated, by that time, almost hopeless. And yet we were liberated, and some of us survived.”

Grayzel is now 83, but she remembers that day in 1945, as she remembers the horrors she experienced as a young girl as a prisoner in Auschwitz-Birkenau, a Nazi concentration camp. She was only five years old when Germany invaded her home country of Poland.

“They say children don’t remember,” she said. “I remember everything.”

It is estimated that 1.3 million people were sent to Auschwitz between 1940 and 1945, 1.1 million of whom were murdered, according to the United States Holocaust Memorial Museum. By the end of World War II, six million Jews, along with millions of others — Roma, gay people, people with disabilities, and members of other groups the Nazis deemed inferior — had been killed.

Grayzel and other survivors say its important to share their stories because there are lessons we still haven't learned from their experiences.

"Why do I think it is important to remember the Holocaust? It is because people didn't think it could possibly happen. ... It is the ultimate of lessons [of] hate," said Dr. Anna Ornstein, also a Holocaust survivor, who regularly shares her story in schools. "You have to teach the Holocaust, and show its relevance to our democracy."

It’s been 73 years since the day Auschwitz was liberated, and ever-fewer witnesses to the Holocaust are still living. What does this mean for our remembrance, and the lessons we take away? What do survivors say we have yet to learn from their stories?