I remember my first science based thought was based on a survival scenario. If you are a small boat going over a waterfall then you need to crawl to the back, grab hold of the boat and just before you hit the water you jump from the boat. Thus saving yourself from a 100ft fall by making a three foot jump. Ta da.
A childhood belief about physics

others believed things like this
- I used to believe that the last line of Row Row Row Your Boat was 'Life is butter dream'.— Mindless Misfit
- row row row your boat gently down the stream...merrily merrily merrily merrily life's a butter bean.— bleeslady
- I used to believe all liquids were water-based with things added to it to make different kinds of liquids.Anon
- I used to think that when a movie was 'based on a true story' it was happening for real then and there— Tom
- i used to think that "the king and i" was a musical based around the life of priscilla presley— erin
- I used to believe that spaghetti grew on trees, based on a pasta commercial from the 70s.— Dianne