A childhood belief about condoms

I grew up in a small town and when I was around 9, walking home from school I came across two giggly high schoolers. Turns out it was their friend's b-day and they'd given her a box of condoms. I walked on, puzzled as to how a condominium would fit into a box and impressed that they'd had the $$ to do so. It wasn't until I moved to the big city and got sex ed in school that I figured that one out.