I came to believe in a flat earth, because I was convinced that the earth wasn't spinning and I kept seeing videos of flat earth associated with a stationary earth. I kind of resented that, because I thought it was making stationary earth look crazy. After a while though I gave in and watched some of the videos. Eventually, I started trying experiments on my own and could see that a lot of it made sense.

For example, something falling off a table and hitting the floor could be explained by a lot of other things, besides "gravity." And that was easy to accept for me, because a stationary earth had already got me thinking about that. You know, if the earth isn't spinning at a thousand miles per hour, you don't have to worry about flying off of it!