Linzer Torte was a troubled child. Although he had a happy home, parents that adored him to no end and his best friend Sprinkles (the animal balloon dragon) and all the cupcakes he could ask for, his mind was plagued with thoughts that the adults never wanted to talk about. It started out as innocent curiosity, but as time wore on, Linny began to realize certain questions made ponies uncomfortable. Because he was a child, they felt they had to dumb down the answers for him, or just refuse to answer at all, telling him that he didn't need to worry about those things yet. But he DID worry about those things and he wanted answers.
It left Linny confused and…lonely. The only one who answered his questions was Gummy, who had grown so enormous over the years, little Linny could just hop on his back and swim out into the pond at Fluttershy's Sanctuary to chat philosophy, albeit in their own language.
Notes:
Linzer is the youngest child among the Mane Six, born years after everyone else due to Pinkie and Party's late marriage and subsequent troubles trying to have children. He has a "sense" just like his mother, giving him insight into the world that no one else has. It's not really predictions, but rather a hyper awareness of the world and ponies around him. He's kind of scared of everything because of this, which is why he distracts himself with his mind. Gummy and Sprinkles are major comforts for him.
He's still a child, and he wants to know so much about the world that scares him. Luckily, perhaps a certain grandparent is not far to give him the push he needs to get out of his comfort zone.