Ralph Troll spent 40 years teaching biology at Augustana College, and he only told the story there twice.
The first time was in the late 1980s, when he was asked to speak to a German class, because he was from Germany.
"It was just kind of part of the story," he said last week.
And then in the 1990s, the college asked him to give a senior-recognition talk. "I'm a biologist," he said. "They didn't want to hear about anything like that.
"I decided: This is a good day to do this. ... That's really the first time I told the whole story."
In all, Troll - who is now 77 years old and an emeritus professor at Augustana - said that he's told about his family's experiences in Germany during World War II five times, which is five more times than his mother talked to her children about her stay in a concentration camp. He'll lecture twice next week, on Sunday at Davenport's Temple Emanuel and on Monday at Augustana College.