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.
Yes, I have told many people to watch it. I just like it. It comes up a lot.
After you see it, you will be incredibly confused. Go online, and read a bunch of summaries and explanations that help it all make sense. Then go watch it again. You'll enjoy it a lot more once you actually understand it.
And if you want suggestions for other movies by Christopher Nolan, I recommend Inception and Interstellar. They're less confusing, and in my opinion, even better than Tenet.
You've probably already seen me talk about them, and you might have already seen them, but I'm saying it either way.