To realize the value of one year:
Ask a student who has failed a final exam.

To realize the value of one month:
Ask a mother who has given birth to a premature baby.

To realize the value of one week:
Ask an editor of a weekly newspaper.

To realize the value of one hour:
Ask the lovers who are waiting to meet.

To realize the value of one minute:
Ask the person who has missed the train, bus, or plane.

To realize the value of one-second:
Ask a person who has survived an accident.

To realize the value of one millisecond:
Ask the person who has won a silver medal in the Olympics.