An 80 year old said what is important in life

Don’t get attached to people who leave you.
Some people will leave you even if you thought you were getting along well with them.
If it is someone you like or care about, you may not want to let go and may even want to chase after them.
But try to hold on and let them go. The fact that they are leaving you means that they have found their own way. Just as you have your own circumstances, they have their own circumstances, their own way of life, and their own life. So when you see someone leaving, think of it this way.
The person who leaves is someone who has completed their role in your life.
And new people will surely come to fill the hole. I understand that it is tempting to cling to what you have lost, but instead of chasing after it, cherish the connections you have now and the connections you will have in the future, and live your life looking forward.