At least twice, I've accidentally set my iOS devices to the Do Not Disturb focus mode. First time made me miss a job interview calendar reminder, leading to me (1) learn there's no way to disable this 'feature', the 'do not disturb' focus cannot be deleted, and (2) setting the DnD-focus-mode-specific wallpaper to something radically different from normal just so I'd spot it faster next time. It did happen again, but the second time I knew what was up even on the lock screen and turned the focus back to normal before it did any harm.
At least twice, I've accidentally set my iOS devices to the Do Not Disturb focus mode. First time made me miss a job interview calendar reminder, leading to me (1) learn there's no way to disable this 'feature', the 'do not disturb' focus cannot be deleted, and (2) setting the DnD-focus-mode-specific wallpaper to something radically different from normal just so I'd spot it faster next time. It did happen again, but the second time I knew what was up even on the lock screen and turned the focus back to normal before it did any harm.