My dad told me (with a straight face) when I was nine that Mt. Rushmore was made in the same way as the Grand Canyon (i.e. millions of years of water carving through stone). For four years I believed him, speaking to no one about it and wondering why the world wasn't abuzz with excitement and awe that a constant rush of water could eventually carve out exact facial replicas of four of America's greatest historical figures. I thought maybe it had been discussed and accepted by people before I was born and no one therefore no one brought up the wonder of it anymore. When I was 13 I finally asked my mom didn't she find the whole thing amazing and she told me the (less than amazing) truth.
A childhood belief about places

others believed things like this
- I was convinced that Indians had dug the Grand Canyon.— Tom Sackett
- I believed one of the greatest dangers you could face was quick sand. I was scared to death of it.Anon
- I used to think it was an amazing coincidence that all my members of my family had the same name.— Raj
- I was born brunette with brown eyes and dark hair, i thought people with blue eyes, had water in them.Anon
- I asked my father what holy water was. He told me it was the priest's bathwater. — Gwen
- I didn't think you could put out a fire with hot water - only cold water would do.— Katti Pytt