A childhood belief about condoms

When my mum gave me the sex talk, she talked about how lots of people had sex just for fun, and not to make babies. I remember her using the word condoms, and thinking that this was an abbreviation for condominiums. I believed for years that as long as you had intercourse in a condominium, you wouldn't get pregnant, and that only people that lived in houses had babies. I didn't actually know anyone that lived in a "condom" so there was little to disprove my theory, until I got a better sex education.