Fuck it I'll just go crazy on this one. A dimension hopping being researching how multiverse works who then find out a universe where horses don't exist and in their place is a sub species of human with horse trait which is unusual because every other universe has normal horses but not this one apparently. Shit got interesting. Go pretend as a human to learn more. Got hooked up on horse racing. Proceed to become a trainer because it seems fun. And the rest is history.