Recently I read about the concept to view one’s life in terms of a more or less given amount of weeks - there is a nice blog article waitbutwhy.com — your life in weeks. This will most likely make you think about what you should (still) be doing and not wait or waste the time.
I think weeks are a nice unit to grasp, and the amount of weeks available in a lifespan is at the same time quite a lot, but also still quite limited, especially when you mark with higher age the past ones …
Of course there are many websites already out there, but I still had to do my own - it allows you to set your birthday (data stays local on your browser) and query the life expectancy (from an external service - here the selected date will go out.
Try and see for yourself at life-in-weeks!