Universes Within Universes

I've been thinking about something. Let's say that microscopic bacteria we cannot see perceive cells and their environment the way we perceive the universe. We know the universe as a place full of enormous planets and rocks. The same could be true for those bacteria: cell components could make up their own universe.

We could be some kind of smart bacteria living in a much bigger universe. Even if creatures that perceive our planets as atoms did something, we wouldn't feel it because the scale would be too large for us to notice the change or impact.

The same goes for bacteria living in cells. They have a certain lifespan of their own, so if something happened to the human body, they wouldn't feel it; it would simply dissolve into the Earth. That's just my thought.