What does Bruce call himself in his head?

What does Bruce call himself in his head is unclear without specific Bruce, but if referring to Bruce Willis, no public information about what he calls himself in his head, and if referring to Bruce Springsteen, he calls himself The Boss as nickname but in his head maybe just Bruce, with question being philosophical about internal self-talk. If question about Bruce Willis with frontotemporal dementia, what he calls himself in his head is private medical information not shared by family, with FTD affecting internal language and cognition, but family says he still has moments of self-awareness. If about Bruce Springsteen, he calls himself The Boss which was nickname given in early days because he collected money and paid band, but in his memoir Born to Run he reflects on self-identity as working-class kid from Freehold New Jersey. If about Bruce in general psychology, people call themselves I in head. So what does Bruce call himself in his head is speculative, with no public answer, as internal monologue private, but Bruce Springsteen calls himself The Boss externally but internally just Bruce, and Bruce Willis internal self-talk not publicly known due to health condition, with family focusing on care not internal monologue details, making question unanswerable with public information.