A few minutes ago it was seven o'clock and I thought I would drink a cup of coffee to keep me awake while I finished up a few things and wrote a letter to a friend.
A few minutes later I thought about refilling my coffee cup and realized it was already after eight and too late to drink coffee unless I didn't want to fall asleep at bedtime.
So I read a little bit.
A few minutes later I looked at the time - quarter past nine! How can that be? Time flies by and I have so little to show for it.
Tick-tock! Tick-tock! Suddenly it is time for bed. Time to go. Time to stop. Time to close the book. Time to move on. Seconds turn into minutes turn into hours and days pass into weeks and weeks into years and years into decades...
Better keep track. Make use of every opportunity.