Pondering other worlds, whether those be the distant worlds in our own universe, or the worlds we can enter through the stories of others.
...
Speaking of which, here are some worlds/stories that I like, in no particular pattern or order (though this is probably in need of some updating):
The Cosmere
Avatar: The Last Airbender
The Legend of Zelda
The Xenoblade Chronicles series
Ender's Game, Speaker for the Dead, and adjacent books
Project Hail Mary
The Remembrance of Earth's Past
Dune
Interstellar
Arrival
Inception
Tenet
Princess Mononoke
Castle in the Sky
Fullmetal Alchemist
Star Wars
...And probably a bunch of others I'm forgetting. This list is not comprehensive.
When you make an interesting character in an RP and then are raring to go, but no one posts after you, and you don't want to just edit the original post with a whole ton of intro writing because then no one will notice it, and you don't want to double post either...