If you have aspirations of living a lot longer than current standards, have you given any thought to what you have taken for granted now that you may have to discard in, say, 300 years?

For example, if the Harry Potter novels meant a great deal to you growing up, how will you relate to people even within your current life expectancy (say, in your 50's) who grew up later than you and didn't read those novels or see the movies because something new came along to replace the Potter phenomenon?

Or consider what could happen over a longer time scale: What if the social ideology of the Enlightenment declines in influence, human societies regress towards the long-term mean, and something like Neoreaction becomes the dominant social model in, say, the 24th Century? If you manage to hang around that long, people much younger than you might want to ask you about your experiences with democracy, equality, feminism and other Enlightenment notions that they read about in historical works, but which they find too alien to relate to.