Aperson with two or more well developed identities has the disorder called

I believe the answer is: dissociative identity disorder.

In dissociative identity disorder, there would be two or more distinct identities that would constantly tried to overtook the consciousness/existence of the patient.
This disorder is considered as a 'severe' condition and it is very common for the victim to experience time skip and not even remembering the things that they have done even when they're awake

So you know what happened and so it doesn’t repeat it’s self