How to live happily ?
You will have a good sleep only when, by the evening, you know you have done everything that should have been done that day; your day was busy; and for the things you missed, you know you have done everything which was under your control to fulfill them. Everything you did was within the frame of your values and the meaning you set for your life.
A peaceful death is like a good sleep.
You will die peacefully only when you look back at your life and you see that you have done everything that should have been done.
A peaceful death is the only valid criterion of a happy life.