I just beat the game last night, and I was curious about the change to the water curse that occurs at the end of the game. At the very end Raz tells Nona that the water curse isn't real, but just something Ford implemented in their minds. Now in the post game, you no longer get grabbed up by the water monster, and instead do a little dance on the water (before teleporting back to where you fell off).

However earlier Ford mentions that he only ever interfered with Lucy and Raz's Dad's mind, yet the water monster curse / fear very clearly affects Raz. Did I miss something or was it just that Raz's dad was very convincing about the water curse to Raz.