I think this is an important story. But it should have the context that the poison of Naziism is potent, and anyone can be affected in the right manner.
Your grandfather's formative years were in a time where security was granted at the point of a sword, and he learned that particular lesson.
We grew up with the lessons of history.
I pity your grandfather, and his poisoned soul. And I fear that children in countries like ours may yet live in such a hellish utopia.