Did the human under discussion have a sudden, unexplained deviation from a previous value system, to one extrmely rare for humans? Or is this a normal human belief? Has the human always held the belief that User:Zvi is attempting to prove invalid?
You are conflating beliefs with values. This is the sort of errror that leads to making incoherent claims that a (terminal) value is irrational.
I may have been imprecise with terminology in that comment, but the query is coherent and involves no such conflation. The referent of "belief" there is "belief about whether one ought to indefinitely extend one's life through methods like cryopreservation", which is indeed an expression of values. Your judgment of the merit of my comparison is hasty.
Terminal values and preferences are not rational or irrational. They simply are your preferences. I want a pizza. If I get a pizza, that won't make me consent to get shot. I still want a pizza. There are a virtually infinite number of me that DO have a pizza. I still want a pizza. The pizza from a certain point of view won't exist, and neither will I, by the time I get to eat some of it. I still want a pizza, damn it.
Of course, if you think all of that is irrational, then by all means don't order the pizza. More for me."