Life is filled with loss.
We lose people we love and care for when they die.
We lose friends from whom we drift apart.
We lose experiences - like the excitement of turning Bar or Bat Mitzvahed, of being newly married, of holding our new baby etc. etc. etc.
We lose our youth and our youthful vigor.
If you think about life - it is filled with loss. Every second is indeed a gift that will never come back and lasted for literally only a second.
The question is - How to best cope with loss?