While some people will be familiar with their dreams, other people won’t be. When some people wake up it is going to be easy for them to remember what took place in most cases and they could keep their dreams alive by writing about what happened.
And for others, they might remember what took place for a short while afterwards and for others, their memory will be completely blank. So during those times when one soon forgets what happened, they are not going to be able to gain any kind of insight from what took place.
The same could be said for the person who doesn’t remember anything when they wake up. However, their outlook could be that they simply don’t dream and therefore they are not missing out on anything.