Here's why:

* The distance to the moon is finite: It's about 238,900 miles (384,400 kilometers).

* Infinity is not a number: It represents an endless, unbounded quantity. There's no "end" to infinity, so you can't compare a finite distance to it.

Think of it this way: you could theoretically travel to the moon, but you could never reach infinity because it's not a place you can get to.