At the age of 59 my friend Bob Boardman wrote, “If the 70 years of a normal life span were squeezed into a single 24-hour day, it would now be 8:30 in the evening in my life. . . . Time is slipping by so rapidly.” 

The difficulty in admitting that our time on earth is limited inspired the creation of “Tikker”—a wristwatch that tells you what time it is, calculates your estimated normal life span, and displays a running countdown of your remaining time. It is advertised as the watch “that counts down your life, just so you can make…