This an exercise that I recommend you do to remind yourself that our time is limited. Look up your age and gender in a life expectancy table. Convert the remaining years to a number of days by dividing by 365. You can use the date calculator to find out your projected date of death, and use a tool such as Days Left for Mac or TimeLeft for Windows to show you each day how many days you have remaining. Each time you see that number go down from the day before, it’s a reminder to use your time well. Obviously, you probably won’t actually die on exactly that date, so no need to worry about getting too exact; the important thing is to get a ballpark number of days and be reminded every day that you have one less. So make each one count! Do something fun, or meaningful, or kind, or valuable in some other way, in every single one.
This exercise was the inspiration for this whole blog. (My answer was 17,011.) More details on the calculations can be found here: http://kk.org/ct2/2007/09/my-life-countdown-1.php