Inside? Tell me what the outside is, then :)

Outside the Game of Life is easy to tell.

Outside the universe ain't. But even though, I can confidently say that we are definitely inside.

But does it make sense to even talk about inside and outside then when talking about the universe?

It makes about as much as uncountable infinite numbers. I can say everything in the universe is within a countably infinite distance of me. Thus, anything an uncountable infinite distance from me is outside the universe.

Not a very tangible idea, but not useless of purpose of reasoning about the affairs of things.

It's a bit of an abuse of notation. Talking about the inside definitely makes sense. (Talking about the outside is a bit like talking about the empty set.)