fnaf4 theory
Here’s my theory... You’re the child of the person who bought the charred remains of Fazbear’s Fright at the auction. Springtrap’s spirit inhabits the Golden Bonnie doll, and has corrupted the once-lifeless shells of the other dolls and animatronics. This is why any of them would attack a child, instead of protecting them like they once did.
How this ties in with the Bite of ‘87, I don’t know...
I’m probably wrong, but then again, I imagine so is everyone else.