He was young.
Being young, is nice. Mostly because you don't have to deal with a lot of the issues that e.g. a house, children and maybe the marriage is not as loving as it used to be.
So he misses being young, but instead of realizing that he was just young. He thinks about what was different and as your responses imply, he blames foreigner for the change. As you expressed that he thinks of you as just a girl, he is probably also sexist and the 50s were much more sexist as it still is.
In other words, culture changed, he didn't and he is old.