Cereal boxes in the old days and today

I like the expression “in the old days”. It seems to me that we no longer use it enough. When we were little, we said that often, I think. Today it just sounds a little funny to talk about our grandparents' times like the old days.

- Dad, how was it in the old days, when you were little?
- In my day, son, cereal boxes looked a lot nicer.