Bovinepawg:
I know this isn't universal, but I'm sure lots of people do it- the going-to-bed fantasy session. Lying in bed, can't quite fall asleep, and 'daydreaming.'
I'm generally very submissive, and my real life experiences/erotic writing/roleplay generally reflect that. I'll gleefully write up dream contracts and rules for my new role as a pampered little piglet.
Occasionally, though, the fantasy is entirely different- that the entire *world* serves my appetites and my needs. Literal entire nations devoting a crushingly burdensome tithe of food and resources to me; entire educational systems devoted to training generations of servants to spend their lives in devotion to me; the entire world's scientific and artistic and cultural output dedicated to worshipping and growing my ass.
The story Future/Perfect on my profile is basically a narrative of this- as 'over the top' as that story is, my brain-version is even more absurd.
When i was a feeder (a long time ago xD) i used to have a fantasy of a feedee being fattened in such a fashion. I did not have an understanding of sub/dom dynamics, within that fantasy, but the imagery would be something like... The entier infastructute of the world would focus on throwing food in her. Propably with conveyor belts, and ships would come and unload their contents on those. That kind of stuff.