During the research for my two books;
and
I did a lot of thinking about the nature of reality and discovered that "infinity" can be conceptualized in such a way that it is "self-explanatory!"
First: Look at the concept of "infinity" as a mind game and mentally go way, way, way out into the far reaches of the universe until you eventually get to the end of things..., and THAT, my friends, would be proof of "A finite universe!"
Now!
If you try and imagine a truly "INFINITE" universe you would once again mentally travel further and further out into the far reaches of the cosmos..., and when you get to the "far reaches"..., go STILL FURTHER and FURTHER and Further and further until you finally say to yourself; "oh, the hell with it," and go do something else!
That, my friends, is how to imagine infinity!