Brexit is like when you and your friends are playing a game and someone decides they don't want to play anymore. When that someone leaves, it changes the entire game and everyone has to figure out what to do next.
In popular culture, Brexit is often talked about in TV shows, movies, and music. Sometimes people make jokes about it because they think it's silly or confusing. Other times, people talk about it seriously because it's a big decision that affects a lot of people.
In some TV shows, characters might mention Brexit when they are talking about things that are going on in the world. They might say things like "Brexit is causing a lot of problems for our economy" or "I don't really understand what Brexit means, can you explain it to me?"
In movies, Brexit might be a plot point - that means that it's something that happens in the story and affects the characters. For example, a character might lose their job because of Brexit, or have to move to a different country because of it.
Lastly, in music people might write songs about Brexit. These songs can be happy or sad or funny, but they're always about how Brexit is changing things in the world. Some artists might use music to express their feelings about the decision, and others might just include it as part of the backdrop of the stories they're telling.