Imagine your life is a 24-hour clock and you can understand how short it is.
For example, if you plan to live 80 years, and you now are 20:
80 years - 24:00
20 years - 6:00
The life timer will show only 6 o'clock in the morning, you haven't yet waken up. Many say the life ends at 40. Not true! At 40 your life timer shows only 12:00, the day only begins at this hour!