You could always associate with causes/groups such that you knew that in your absence the cause would go on, and have a life dangerous enough (taking chances on interesting experiences, etc.) such that your half-life was short enough that this didn’t become a problem. Though that might not be ‘living as long as you want’ for some people.
I don’t know if this is a new problem. People lose their purposes in life all the time. They tend to find new ones, especially when groups of people are involved. These things are remarkably fluid, and do not necessarily correspond one to one with external physical reality.
You could always associate with causes/groups such that you knew that in your absence the cause would go on, and have a life dangerous enough (taking chances on interesting experiences, etc.) such that your half-life was short enough that this didn’t become a problem. Though that might not be ‘living as long as you want’ for some people.
I don’t know if this is a new problem. People lose their purposes in life all the time. They tend to find new ones, especially when groups of people are involved. These things are remarkably fluid, and do not necessarily correspond one to one with external physical reality.