Pretty sure our entire universe is just a cell of a larger something. Or were in a simulation. Either way.
A while ago I had a mini existential crisis about how things existing at all just makes no sense, and eventually concluded that things existing at all means that “nothing” is in some way unnatural and has a chance to become matter, which would then imply infinite universes as there would have to be infinite “nothing”, since that’s what would be outside our universe.
So yea, I’m thinking it’s probably large somethings for forever, always getting larger.