It's a bit of a controversy because... the Brits maintain Deaf of Deaf don't go through a Deafhood journey because they are already born in the Deaf culture, and already has an identity. Those who felt lost in the world usually go through the Deafhood journey. The Americans, however, disagree with the Brits. The treatise has been written, but the application is a bit of a struggle.
So, yes, the concept of Deafhood is based on Paddy's personal experience.
I refrained from expanding more on the topic because I am not a "Deafer than Thou" type who seems to troll me when they gets the chance.