So I was just in Brainiac mode, accidentally getting the sixth notebook example wrong and thinking "screw it, let's get the rest wrong" when the notebook just got reactivated but the game thought I was still in the overworld. So I got trapped in the notebook screen with no mouse. By the way I only got 1 wrong (until I did this one, when I got 6 wrong) and yeah. There's a bug. Hope it's patched! Bye!