Written, shot, and edited all within 5 days.
Based on the two-sentence horror story: "Yesterday, I wrote the number 69 on my wrist as a joke. Today, it's 68 and it doesn't wash off..."
Lewis is the personification of death, almost like the Grim Reaper... growing closer and closer to Arthur as time closes in.
The flashbacks Arthur has about Lewis towards the end of the film is a nod to the director's favorite film, "JOKER".
When Arthur says "You're killing me, Lewis", he unknowingly predicts his own future. Lewis does indirectly kill Arthur as Lewis is the sign of nearing death.