haha i will be very old after 50 years and it wont be that fine as i want to make money while i am young and spend it also ! but talking about bitcoin its just immortal as the technology is there and world is being digitalized day by day and soon it will become a global currency 
However I feel differ slightly with name immortal to its and technology, for example could be enough only see the tons of disused cell exist out there, and that is only an example.