Why was Hitler so mean?

1. Rough childhood driving him to resort to narcissism to escape depression.
2. Narcissism driving him to blame others for all problems.
3. Methamphetamine kicking the regular madness to the next level.

https://en.wikipedia.org/wiki/Adolf_Hitler#Early_years

[At the age of 6,] onset of intense father-son conflicts caused by Adolph’s refusal to conform to the strict discipline of his school. Alois tried to browbeat his son into obedience, while Adolf did his best to be the opposite of whatever his father wanted. Alois would also beat his son, although his mother tried to protect him from regular beatings.

https://www.quora.com/Why-is-there-evil-in-people/answer/Harri-K-Hiltunen

… the infantile narcissism will be preserved as a kind of psychological fortress to protect the child against the vicissitudes of its intolerable life. Thus children may become evil in order to defend themselves against the onslaughts of parents who are evil.
… the longer we continue to make the wrong decisions, the more our heart hardens. … with each step along the wrong road it becomes increasingly difficult for them to admit that they are on the wrong road
… When they are in conflict with the world they will invariably perceive the conflict as the world’s fault.
… As life often threatens their self-image of perfection, they are often busily engaged in hating and destroying that life—usually in the name of righteousness.
… it is out of their failure to put themselves on trial that their evil arises. … We become evil by attempting to hide from ourselves. Evil originates not in the absence of guilt but in the effort to escape it.

https://en.wikipedia.org/wiki/Narcissism#Normal_and_healthy_levels_of_narcissism

… a moderate level of narcissism is supportive of good psychological health. Self-esteem works as a mediator between narcissism and psychological health. Elevated self-esteem, in moderation, supports resilience and ambition, but excessive self-focus can distort social relationships.
Destructive levels of narcissism … feelings of entitlement and superiority, arrogant or haughty behaviors, and a generalized lack of empathy and concern for others.

https://en.wikipedia.org/wiki/Narcissistic_personality_disorder#Subtypes

… Grandiose/overt: the group exhibits grandiosity, entitlement, interpersonal exploitativeness and manipulation, pursuit of power and control, lack of empathy and remorse, and marked irritability and hostility.

https://www.psychiatrictimes.com/view/methamphetamine-dictatorship-hitler-nazi-germany-and-drug-abuse

Morell’s notes reveal that he put Hitler on a regimen of Vitamultin – a preparation containing glucose, vitamins, and sometimes the methamphetamine Pervitin – and prescribed dietary restrictions, bloodletting, leeching, enemas, and the morphine derivative Eukodal to relieve the GI symptoms. Sedatives (for sleep) and testosterone (for sexual potency) were also among the considerable number of drugs (over 40 different kinds) Hitler took over the course of his adult life.

Does methamphetamine use increase violent behaviour? Evidence from a prospective longitudinal study

Conclusions: There is a dose-related increase in violent behaviour during periods of methamphetamine use that is largely independent of the violence risk associated with psychotic symptoms.