I might well have been attending Northwestern before I fully appreciated that Chicago wasn’t in Michigan.
Until recently I had the idea that the Rock of Gibraltar was an island. I blame my misconception on seeing all those “get a piece of the rock” Prudential commercials as a kid.
I have no explanation for this one but. I’m good at geography. I aced a class on contemporary Africa in college. Yet you mention East(earn) Africa and my mind automatically puts Nigeria there.
Speaking of Brazil, I remember being quite surprised to learn that Brazil is bigger (i.e. has more landmass) than the continental United States.
I’m always surprised how far south Canada goes. Ottawa is at the same latitude as Milan. There’s also the Edinburgh is west of Bristol thing. And I once calculated that on the June solstice the sun sets in Rio de Janeiro before it sets in London. Brazil goes a long way east. And it gets pretty close to the Pacific, too.
“The sun has riz, the sun is set
And here we are, in Texas yet.”
(Burma-Shave?) Probably not, but it’s an old saw about how long it takes to drive across this state. On that note, El Paso is closer to LA than it is to Houston. Edit: and San Diego too, as noted by @Ruken.
I once drove 400km north from Toronto to Sudbury. Along the route you pass over the 45th parallel. I remember thinking, “I’m halfway to the North Pole!” It certainly felt like a long, arduous drive, given how crappy my car was.
But the 45th parallel is below Seattle. Below Sioux Saint Marie. And almost all of Europe north of Spain is above the 45th parallel, leaving nothing but open ocean and Antarctica.
Contrarily, 45 degrees south cuts through only the southern tips of South America and New Zealand.
Speaking of which, back in the 1950s, Jimmy Olson got a super-brain and told Superman to dig a hole in Antarctica and move millions of tons of junk from the North to fill it up. Why? Some writer looked at the globe, saw how uneven the land distribution was, and thought that it made the whole Earth unstable unless Superman put it right. A story plot and a geography lesson in eight pages. Those were the Good Old Days.
The former Soviet States, and the former Yugoslavia, and the former Czechoslovakia are all things that went over my head when they reformed back to their individual countries.
Nobody sat down with me and explained what had happened and what it meant and what their names were. I feel it should have been taught in schools, or in documentaries aimed at ignorant folk like me.
It was years after that I looked at the map of Europe and saw all these countries I had never heard of before, and it took a while before I started to piece it together. But the jigsaw of them all has never settled in my brain.
It was just up the road from my High School.
I’ve driven from just north of Windsor to Thunder Bay. It’s a long, long drive. Ontario is not a small province. I don’t recommend it in one trip, no matter how beautiful Lake Superior is. I might have seen the face of God. 
Coulda been worse - didn’t have to go to Kenora, and it was late spring.
I’m always amazed at how much of New Jersey is north of NYC. It just feels like you should travel north from NJ to get to NYC, but in fact, for a considerable portion of the NJ population, NYC is due east (or even south-east) of them.
I think one geographical misconception a lot of people have is thinking that North and South America lie on a fairly directly north-south axis. The reality is South America is much further to the east than North America. If you started in Tampa, Florida and traveled straight south you would miss South America’s western coast.
California always befuddles me. I was born in a town in eastern Oregon about 30 miles from the Snake (Idaho border) which is on almost the exact same meridian as San Diego. And a flight from Seattle (Sea-Tac) to Honolulu is only about 130 miles longer than a flight from LAX to Honolulu because Seattle is so much farther west.
Even more befuddling to many people: A flight from San Francisco to Honolulu is actually shorter than a flight from LAX.
I was surprised when we flew from LAX to Seoul theat we flew up the coastline then over the ocean then more or less down the coastline instead of straight across.
I find it weird that This is in Wisconsin. I stopped at it once or twice.
The first time I traveled to Brazil, I was amused to learn that it was 3 hours ahead of US East. I realized that the Western Hemisphere in my mind was rotated counterclockwise so that North and South America were lined up.
For a long time, I thought that Korea was down by Vietnam.
I assumed my home town of Edmonton would be about the same latitude as northern Scotland, and north of Oslo and Stockholm as well. In fact it’s about the latitude as Liverpool, Manchester and Hamburg. And the Scandinavian capitals are much, much farther north.
This article shows “the most accurate world map ever made” (using a newish technique for translatong spheres). It shows the correct orientation of the Americas, which is surprising.
I remember reading that one when I was a kid! (meaning it must have been in the 60s) Anyway, I was very impressed with that plot device, and then a few decades later I realized: Moving even a few hundred mountains to Antarctica is not going to make an appreciable difference in how lopsided the hemispheres are.