I apologize if this question is in the wrong forum, I am not a math student and have no clue which branch of mathematics this question would fall under. In fact my profound ignorance of math makes it so I don't even know if this is a stupid question till I ask it. Since most problems that nag at me in insomniac moments are not number related, I can easily track down more information if I can't figure the answer out myself, but here I have had no luck with Google or any of the basic explanations of series and sets I've found online, so even a few search terms to help put me on the right track in lieu of an answer would be helpful.
If I remember right the series of natural numbers 1,2,3,4... is an infinite series, and the series of negative numbers -1,-2,-3,-4... is an equally infinite series. But doesn't this make zero the midpoint of a series that runs into infinity on both ends? This feels paradoxical to me since I thought it was impossible to calculate a midpoint to infinity.
So anyway, I assume I must be making an error in my premise (searching so far indicates possibly by misunderstanding the definition of the word "infinite" as it used in math in general or with number series specifically?) but I don't know exactly and am stuck in trying to track it down. Again,sorry if this is an idiotic question but for whatever reason it's nagged at me for a day or two and I figured I'd take a shot and see if anyone here could explain it to me or set me on the right scent to find out more on my own.