- Make a list of all the books you own. Find out your reading speed, i.e. no. of mins per page. Roughly estimate the amount of time it will take you to read all the books you want to read. (A).
- Do the same with your DVDs and movies i.e. estimate how much time it'll take you to watch/listen to these. (B)
- Add about 25% to each of these counts, to account for newer books and movies of the future. (A', B')
- Assuming an average life expectancy of 75 years, calculate how much time you've got left taking up valuable planetary space. (C)
- Estimate the fraction of the day you can spend in a day reading+watching+listening. (D)
- if (C*D <= (A'+B')), it's time to retire.
Maybe you don't read, maybe you like to travel, to act, to paint, to bungee jump. But the general principle holds. Otherwise, you'll find you have run out of time.
You really want to find that out? Hopefully, you'll have high senility by then.