As we all know there three grayed out event by default when you create a blueprint class. If you implement one of them , the derived classes of that class will automaticly has a parent call connected to that event.But if you disconnect the connection in the derived classes won't automaticly override the event.So you will see a event(still grayed out through) doesn't connect to any thing but still can do things. I found this recently when I wanted to prevent a derived class to perform doing it's parent's "Event Tick". I was confused because the class still do its parent "Tick" until my colleague told me "Tick" was not overrided. It would be more userfriendly if these event can be automaticly overrided or at least give a warning.