I thought Indonesia was a fictional country, and one I had made up at that.
To make matters worse, a suburban upbringing before widespread internet adoption allowed me to maintain this intellectual charade for an embarrassing amount of time. It wasn't until we were on vacation one year in the early 90s and bought a little wooden frog tchotchke that had a "Made in Indonesia" sticker on it that I learned the shocking truth about the nation-states that comprise Southeast Asia.
And for the coup de grace, while growing up, when encountering someone living extravagantly my family would mockingly accuse them of being the Sultan of Brunei behind closed doors. So I knew Brunei existed, but not Indonesia. :'(
The same thing happened with Micronesia but that was seaQuest's fucking fault.