When an attention seeking emo/wemo tries to go so many days without cutting themself, then they fail. (They go back to day 0)
Whenever something bad happens, no matter how pointless, say 'Day 0' to mock the attention seekers, but also as a sign of respect to people who cut because of mental illnesses.
Luke: Damn I just stubbed my toe!
All: DAY 0!
Kristen: I forgot my homework!
All: Day 0!
Sam: I'm on Day 41! I hate that number!
All: Day 0