I once saw people start their month with 0 on their bank account, and live in the negative monthly credit their bank allows.
Them having a job (luckily), means they just about manage to fill that debt back at the end of the month, covering the debt and the small bank interest.
They end up paying the bank money bit by bit every month, yet they stay locked in that negative money pit.
It’s like being permanently broke, and it all started with one a bad month of extra payments…