For a lot of people the first conscious act of the day is reaching for a device, and whatever the mind was going to be gets decided by strangers inside ninety seconds.
Which makes this less a description of temperament than a description of a routine. Peaceful mornings mostly belong to people who protected the first ten minutes, not to people who happen to be calm by nature.
The protection is unglamorous: phone in another room, a slower first task, nothing that requires an opinion.
Tomorrow, delay the first screen by ten minutes. You'll find out quickly whether the peace was ever about your personality.