It was inherited from the common ancestor that it shares with Ruby, up to the accident at the secret Nuclear Research facility which divided it the two, giving

It was inherited from the common ancestor that it shares with Ruby, up to the accident at the secret Nuclear Research facility which divided it the two, giving Ruby all of the sweetness, optimism and light, while Rust took the bitterness and dark gloom. RUby, RUst, yeah? That's why you never see them in the same room.