#da lore question

Okay so this is something I’m still very unclear on:

Do all dreams take place in the Fade? Or only some?

They talk about the Fade as ‘the land of dreams,’ but Dorian says ‘the first time I went to the Fade...’ when he tells his story of the very polite demon he met, implying it was something that happened later when he was old enough to remember. The Wiki says all living beings except dwarves go to the Fade mentally when they dream, but only mages reliably remember it. 

So are all dreams in the Fade, and maybe a bunch are just forgotten? Or are some dreams only in minds? Or maybe all dreams are in the Fade, but in the DA verse people only sometimes dream? Maybe some nights they don’t dream at all?

And what, then, makes Harrowings so special? Do they push a mage into the Fade with a giant ‘kick me’ sign on their back? Or is that the first time the Apprentices have ever been to the Fade? And how would they not go to the Fade before that?