A really strange thing about Boltzmann brains is that if you suppose their existence, then the question "Am I a Boltzmann brain?" becomes complicated. It makes

A really strange thing about Boltzmann brains is that if you suppose their existence, then the question "Am I a Boltzmann brain?" becomes complicated. It makes sense to ask "Is there a human thinking the thoughts I am thinking?" and "Is there a Boltzmann brain thinking the thoughts I am thinking?", but if you suppose the answer to both is yes, then when you ask the question "Which one am I?", there's no pure logic you can follow within your mind to answer that question, because both the human and the Boltzmann brain are in the same mental state and any logic either of them follow will be followed by the other, and any logic that comes up with a definite answer must be flawed because it comes to a wrong answer for at least one of them. Of course, it's not particularly useful to consider the Boltzmann brain version of yourself because a Boltzmann brain's decisions don't have any consequences. Time is better spent considering decisions by the consequences of the human taking them. Maybe this implies that you should choose to define "yourself" to refer to both your mental state combined with the ability to make decisions of consequence, and then you can safely disregard the strange kinship you may have with a Boltzmann brain. Though now this line of thought invites interesting questions about how to define what makes a decision consequential, and what exactly makes human decisions consequential...