Many developers have the wrong mental model of an event.
Very often they think about an event as 'something that happened in the system'.
This definition isn't ideal, as it only allows to represent state changes.
A better definition is:
An event represents a meaningfull business decission taken, which alters the state of the system.
This definition allows to represent these decissions explictly and let the system adapt to them.
This makes distributed systems design a lot easier, and opens up new opportunities as well. a.o. polyglot persistence.
Bad: SalesOrderChanged, DeliveryCreated
Good: SalesOrderBooked, DeliveryConfirmed