When I was a child, my family occasionally rode by a neighborhood about a mile from where we lived. That neighborhood had rows of virtually identical houses. I'm sure such things are common some places, but in my home town at the time such arrangements of houses were quite unusual, that one neighborhood being the only place I'd ever seen them back then. Back then I guess it was current to consider Mars as the quintessential alien place, and anyone who seemed really different or not "in the know" might be asked "Are you from Mars?". I guess that might explain the notion I got back then. That neighborhood of rows of virtually identical houses must have seemed the most unusual place I'd ever seen at the time. I got the idea that that neighborhood was Mars, and I remember thinking of it as Mars for quite some time.
A childhood belief about places

others believed things like this
- when I was growing up I truly believed that my neighborhood was the only neighborhood with "THE CORNER"— Brid
- i used to believe anyone who didn't live in my neighborhood was rich.— Spencer
- It never occured to me as a child that teachers lived in houses. I thought they lived at school...— Heidi, Pittsburgh, PA
- When I was a kid I thought if I bit my finger off and swallowed it it would pop back into place— Mike
- i used to believe that public houses were just houses were the public could go and liveAnon
- I remember thinking that the "Nude Furniture" store was some sort of naughty place. — Texas Rocky