I remember being four or younger when I first came up with this.
It worried me that the universe was infinite - or rather, because 'infinite' was perhaps not in my vocabulary, it worried me that space should be black forever. Surely it couldn't just go on being black. Everything had an end, surely... although obviously the universe didn't stop, because what would be outside it? This was my solution. After space had stretched on for a long time and way, it stopped being black, and there was a kind of barrier. After that, it was white. Then it was probably brown. And then yellow. I don't remember the exact order after that, but I suppose I assumed that you could go on inventing colours infintely, or perhaps repeat a sequence of them infinitely, and that that would resolve the problem.
A childhood belief about outer space

others believed things like this
- I used to believe that a long time ago, just like in old pictures, the world was black and white loolAnon
- I thought that old movies were black and white because the world was black and white then. — K
- I used to think that the old days were actually black and white because of the old black and white pictures.— Leigh Taylor
- When I was little I used to believe that black people saw in black and white. — Chelsea
- As a child I used to think that the sea was infinite.Anon
- I'm black, so as a child I used to assume that white people pooped peach the way I pooped brown.— Rick