Rusty Morphed Into A Younger Brother

In the original 1983 Vacation movie, Rusty was the older brother in the Griswold family. But in Christmas Vacation, Rusty became the younger brother. It is unclear why the writers decided to make this change. Many fans might not have noticed this change.

In the original short story "Christmas 59," Hughes does not distinguish which child is older. It seems to be left up to interpretation whether Audrey or Rusty is the eldest. Perhaps the writers made Rusty younger to shape the dynamic between him and his sister.

It Was One Of Two Christmas Movies Released In 1989

When Christmas Vacation came out, it was not a popular year for Christmas movies. In 1989, only two Christmas movies were released. The other film was John Hancock's Prancer, about a woman who found Prancer the reindeer in a forest. Even stranger is that Johnny Galecki (who played Rusty) starred in both movies.

Usually, dozens of Christmas movies come out in November and December each year. For example, in 2017, Hallmark alone made 28 movies. Perhaps part of the popularity of Christmas Vacation was a lack of holiday films during that year.