So You Had A Party and Didn't Invite Me?

I am nursing a hurt, and am currently unsure what to do with it.
Someone I know, someone I considered one of my friends, held a fancy holiday party and didn't invite me.
Very pointedly didn't invite me.
Which confuses me. If we were casual acquaintances who knew each other through work I might have been miffed to have been passed by, but I've thrown enough soirees with people from work to know you just can't invite EVERYONE. So if our friendship was of casual standing, I guess I would understand it. Or be less put out by it.
I would also be less confused by these events if this person hadn't invited many, many random people from the office - some of whom were blatant attempts at networking (so I get those), and others who were very weird choices. People way down the ladder, without much previous interaction with this person.

In discussing with a mutual friend I expressed that what I would have to take away from this event that I was wrong about our relationship. That we are not friends. Which is disappointing but seems very likely true.

Women are so much more difficult than men sometimes. Men are straightforward, men are direct. With women there are subtleties and tones, there are nuances of meaning behind what we do. So few women operate without these games that when I meet one who does I nearly want to get BFF tattoos on the spot.

I guess it's all a big "Whatever". I was wrong. We're not friends.

Now the question is, do I reciprocate and not invite her to something.....or be the bigger person? After all, if we weren't friends, I certainly wouldn't invite her. I am female enough to truly consider the first option. I like to think I'm enough of an adult to actually DO the second.

We'll see how big of a child I am.