Have you ever wanted to break a bad habit or start a new one? The YouTube series *21 Days Theory*, created by Jubilee, explores this very idea. Based on the popular belief that it takes 21 days to form a habit, the show brings a diverse group of strangers together to live in a house and pursue a common goal. Each season tackles a different challenge, from quitting social media and getting fit to learning a new skill. Viewers watch as the participants navigate intense personal struggles, dramatic group dynamics, and the immense difficulty of achieving real change. It is a compelling social experiment that tests their willpower and reveals their vulnerabilities under pressure. The series has ended, but sign up for a reminder just in case it returns.