Trains ran past the Hudson River that I lived near as a boy-- they still do, in fact. I always used to think that clouds were a product of pollution-- that the trains puffed smoke and steam, which stayed up in the sky to form clouds. I asked my mum about this, and she agreed with me.
I at the time was very proud of myself-- I'd figured out a force of nature, and was thereby smarter than all of the kids in my class. When my teacher asked said class about clouds-- and what they were, I immediately raised my hand and stated my theory on cloud production.
Needless to say, I didn't believe her for the longest time, 'cos my mum told me I was right.
A childhood belief about weather

others believed things like this
- I used to think the clouds were made of the steam that comes out of the factory smoke stacks.— TJ
- My little brother once asked my mother when we past a couple of factories.. if the factories made clouds— nicky
- I used to believe that when it would be raining the white clouds lost to the dark clouds.— janet
- I used to believe that clouds came from the smoke that came from the factories. — Anela
- I used to think that clouds were caused by cigarette smoke— Monkey Dave
- i use to think that the smoke that comes out of factories was how clouds were made.— Kyndra S.