How is the Universe Never-ending?

When every me and my cousin think about how the universe is never-ending it hurt our brains. My thought process is I start here so all I have to go is here. But the finish line just keeps moving away. My cousin was thinking about this and said it's the only thing that never ends. Of course this is not true because my other cousin answered "No the circle goes on forever to." Now I'm thinking why doesn't thinking about a circle hurt my brain? It just maybe because we can see the whole thing maybe it's not the thought that it's never-ending but the thought that we can't get to the end of it. Did that make any sense?