@JohnBrady Beatrix's first flight was at 3 months old. I spent all day with her at the Denver Museum of Art.
Her first international flight (to Norway, no less) was at 6 months old.
Her first fancy restaurant was at 9 months old.
She's always known how to behave in these types of spaces because she has always been in these spaces.
Yes, a very privileged statement I know. But, the point is that if you expose kids to this stuff early and often they learn the expectations organically. The problem often is that folks don't even try it when they are babies/toddlers and therefore they don't learn.