You may think that you already know what's the opposite of "DISABLED", but with MySQL Event Scheduler you'll be wrong.
In fact MySQL Event Scheduler may have three different states:
DISABLED - The Event Scheduler thread does not run . In addition, the Event Scheduler state cannot be changed at runtime. OFF (default) - The Event Scheduler thread does not run . When the Event Scheduler is OFF it can be started by setting the value of event_scheduler to ON. ON - The Event Scheduler is started; the event scheduler thread runs and executes all scheduled events.
So if you're going to find it in the DISABLED state and instinctively set it to ENABLED you'll end up with a non-starting MySQL daemon.
Be warned and stay safe out there!
: When the Event Scheduler is not running does not appear in the output of SHOW PROCESSLIST