We never see Americans having to "explain" what Halloween or Thanksgiving is, even when they are knowingly facing a global audience.
Bit idea: whenever a Seppo mentions "Halloween" or "Thanksgiving" or "July 4th", simply say, "What is that?"
Additionally, people could contribute things like subtitles or translations, so others can discover media from each other's countries that would never be available through mainstream streaming.
This is a really good and important thing. More people should do subtitling. In fact, right now I'm writing a presentation about my efforts to translate Japanese anime into Norwegian.