Expanding the Universe into itself

Sometimes when I’m feeling down, I wonder what the universe is expanding into. Think of it like blowing up a balloon – it gets bigger in the space around it, whether it’s a room or outside. I read somewhere that the universe is expanding into itself, but that seems strange and confusing to me. I guess it’s hard to picture everything with our limited brains. Thinking about this question just makes me feel even more down.

[What is the Universe expanding into?](https://bigthink.com/starts-with-a-bang/what-universe-expanding-into/)