That's what I suspected, thanks for making this observation. I wonder if others can chime in with anecdotes?
Certainly I've known several people who were held back by forced labor in the countryside, but later went to grad school in the US. They were a little younger than the professor in the OP, so it didn't affect them as much.
Certainly I've known several people who were held back by forced labor in the countryside, but later went to grad school in the US. They were a little younger than the professor in the OP, so it didn't affect them as much.