My own theory of Discord's backstory · 7:45pm Sep 1st, 2014
You know, Discord was always so chaotic that you could never tell who he really was before. So I present to you a theory. This theory also outlines some of the HiE myths, stories, and fics that many people have told.
There were two humans that existed in Equestria. Their names were Max and Reginald. Both of them were mad scientists (and lab partners) looking to make their own version of magic using chemicals in their laboratory. They've done trial-and-error for years until finally coming up with the perfect solution. When Max inhaled the fumes from the chemical, he was able to use magic that was unheard of at the time. However, when Reggie inhaled the fumes, he almost died. He went into a coma and had to be sent to the hospital for a long time.
Now, Max had been experimenting with many spells. Simple levitation, transformation, and his favorite spell, chocolate rain. One day, he decided to test out an immortality spell. Let's just say it worked, but it had a slight side effect. What I mean is, he turned into Discord. As for Reginald, he's been hospitalized for a while and will soon return.
If you guys have a different backstory you want to share, please feel free to post in the comments below.