When I was in like third grade I got a used Pokemon Saphire game because I lost my old one. I decided to play the existing file and was amazed at how good it was. He had every Pokemon, a bunch of level 100 legendaries, tons of rare candies, and 60 Master Balls. I was stupid and believed that he actually worked hard to catch every Pokemon and get level 100 legendaries, but I was stumped as to how he got the Master Balls, since there's only one in the game. I asked my friend and he said "The previous owner probably used Action Replay"
Since Action Replay is a cheating device where you insert codes, a lot like Game Shark. Anyway, since Action Replay at the time was a pretty new program, I of course, had no idea what it was and that it was like Game Shark, which I had heard of. I took the "replay" part of Action Replay literally and assumed it was a program that let you play any part of the game over and over again and what happened during those replays would affect your current data. So I thought that he replayed the part where you get the Master Ball 59 times to get 60 of them.
A childhood belief about computer games

others believed things like this
- I used to believe that the game The Legend of Zelda: Twilight Princess was the longest game ever.Anon
- I used to believe the the tooth fairy was a Pokemon fan because she got me Pokemon Crystal for my lost tooth— Pokemon fan
- I thought live-action films were very, very well-drawn cartoons.Anon
- I used to believe that when i died it was like a super mario game... I had a certain number of lives.— David...waffles
- When I was a child I used to believe that when I played video games my real world changed like the game. — J
- On TV game sows when they said the winners were chosen "at random" I thought random was a town.Anon