Beautiful people/celebrities. I’ve heard the names (Brad Pitt, Beyoncé, Kardashian, etc., etc.) - but I so tune out the information that if you were to show me pictures or give me biographical details I couldn’t match them up.
This. I regard Chemistry as black magic; people that understand it are in league with the devil.
Yeah, I can sit in my doctor’s waiting room and page through People Magazine, and not see a single name or face I recognize. Well, name. The faces are all the same, just with different hair style
I don’t know most stuff about everything.
If fact, there’s more I know nothing about than stuff I know something about.
My ignorance is not only profound, it’s supremely profundis.
I can spell but! 
What I don’t know far out weighs what I do.
Any history other than US, European, or ancient history (Greeks, Romans, Egypt etc)
Math beyond Calculus I
Literature except for a few American and British authors.
The list goes on and on. I learned what was necessary to hold a professional job and that’s it.
The same things people sitting at their computer for hours are doing.
Porn?
If she treated you like that I can see why you “WERE” married to her…
No you can’t, “butt” has 2 t’s! 
A late uncle of mine – formidably and almost terrifyingly knowledgeable about most things – said that knowledge-and-understanding-wise, he had three extremely weak areas: which he summed up as “maths; music; sport”. The same goes for me – along with, in my case, a number of other profound-ignorance-zones.
Sports are a good one. I always suck at that in Trivial Pursuit. Last time we were playing I started answering every sports question with “Derek Jeter”! Of course I lost. 
Philosophy. One of those things I was going to get around to reading about someday.
Reality shows. Never watched a single episode of any of them. I’m aware that the Kardablahblah family exists, but have no idea who is who.
No no. If it’s a baseball question the answer is always Ty Cobb and if it’s football the answer is Jim Brown.
Pokemon
Fashion
Playing a musical instrument
Engines
Dancing
In fairness, no one really understands organic chemistry. It’s all part of an elaborate scam to give otherwise untenured professors employment. The trick is to realize that it’s all made up, and that it is intentionally made so horrible that everyone represses the memory of it. Think of it as academic boot camp without the pushups.
I have 38,000 hrs played on one video game, if it were ported to mobile that number would be over 100,000. That equates to 11.4 years of my 26 year existence.
Anyway, much to my father’s chagrin, I have no idea how a car works and am painfully ignorant about women (hence the videogames) and geography, even in my own neighborhood.
Everything else I can hold my own.
I didn’t know how much I don’t know until I entered college and started learning a little about various subjects.
Before entering college, I knew it all…
After leaving college, I felt as though I did not know a thing!
Marine Physchology
Black Magic
Extra Terrestrial Languages
Nuclear Fission
Picking out matching clothes
Speeling
Stealth Bragging
If you’re ignorant about women you can hold your own as well.
Forensic mineralogy
That’s pretty terrible of her.