When I was four years old there was a great deal in the news about Cuba and about guerilla warfare and guerilla troops and guerilla tactics. To my backwoods, mountain-bred (Ouachita Mountains, on the Arkansas/Oklahoma state line) ears, this sounded like gorilla warfare, gorilla troops, etc. I listened, silently wondering for months how they were able to train the apes to use machine guns and machetes. Imagine my dismay when I finally asked my mother how the training was accomplished and the difference in gorilla and guerilla was explained to me.
It was years before I got over the embarrassment felt when my assumption came to light, (truthfully, it still niggles at me more than a bit.)
To end on a lighter note... although I am now 46 and cognizant of the difference in a guerilla and a gorilla, I still picture the ape when I hear the fighter described.
A childhood belief about wars

you weren't the only one
83 of you believed this
- I thought “guerrilla tactics” meant fighting like a gorilla— beating your chest and that sort of thing.— Kai
- I was convinced that Gorilla soldiers in Vietnam in the 70's were real Gorillas attacking other Soldiers.— Mario
- that Guerilla Warfare was called "Gorilla Warfare" and it's about fighting gorillasAnon
- From a TV news program about freedom fighters, I though that `Gorrillas` could use guns.— adrian
- That "guerilla warfare" involved real Gorillas.— Geoffrey
- I used to beleive that gorilla wars were fought by gorillas.— Professor Luke