Exactly, it's hard to understand infinity, humans always need a finite limit to understand something. For example, what would you believe more:
The universe is 20,000 Sextillion miles across, and we're at the center, about there.
The universe has no limit and there's no edge.
Most people would prefer the first one, even though that's impossible, if you travelled that far you might make it to another solar system if they were 5x closer. There really is no limit to the universe that anyone can comprehend. People need their limits, and when they're refused, they need something else to believe. Hence where they preach the Big Bang is bullshit and that the Earth is flat and the center of the universe which ends after Neptune. It's one of the most hotly debated subjects where I'm at, everyone's trying to find out what happened for the universe to exist. I think the Big Bang might not have happened, the universe could have always been here and the Big Bang was just an expansion. The universe is infinite because there is NO limit to anything. People don't get, the universe is EVERYTHING. Imagine the biggest thing you can. Perhaps the sun, which is massive. It could take either 5 suns to fill the universe, or it could take 150,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 suns to fill the universe. Absolutely nobody knows how big the universe is, nobody knows if Martians don't exist, nobody knows anything. We're just starting to explore the universe, we don't know if there's any possible life in the universe other than us. We're fickle creatures.
Picture it like this, you're an atom. The smallest thing that anyone can think of. It would take an insane amount (175,000,000,000,000,000,000 to the power of 999,999,999,999 perhaps

) of you doubled over to reach another galaxy, stretched out atom by atom. And that's if you were 20 feet tall and squished into the tiniest possible thing ever. The Big Bang theory is not possible the universe was made from NOTHING at all, there always was and will be something.