It's what they see. They see what others don't see, they work towards what others allow them to work towards too.
They train harder than what, than they limit others that are average too. They keep seeing that version of themselves that nobody else can see it and they keep working towards it even when the result is nowhere to be found.
That is how you know those that can be extraordinary, when they keep up with that level of results, you wonder why they are working so hard like that even when they are not in the right path but they still work hard and show up so that they get the level of results they always wanted in their life.
Life has always been designed, to work extra and be smart at what you do.