Pain in life is inevitable but suffering is not. Pain is what the world does to you, suffering is what you do to yourself [by the way you think about the 'pain' you receive]. Pain is inevitable, suffering is optional. [You can always be grateful that the pain is not worse in quality, quantity, frequency, duration, etc]
Peace comes from within. Do not seek it without. It can be argued that peace and happiness comes from the subjective internalised perspective of realizing things could be worse and being grateful they aren't. The alternative view that peace and happiness comes from the objective external perspective of having more and better things than at present, while important for growth, can be a never-ending source of jealousy, dissatisfaction and disappointment. A balance of the two, where people are grateful for what they have while striving for more seems the best blended perspective.
Comparison with something that is better is the thief of joy. Comparison with something that is worse is a joy - full of relief and gratitude! You cannot always choose what happens to you or your circumstances but you can always choose your attitude by what you choose to compare your experiences or circumstances to and therefore how you will feel!! We can make any experience either a heaven or a hell by what we compare it to. Our emotions are 'an inside job!'
And some of your elders remember pleasures with regret like wrongs committed in drunkenness. But regret is the beclouding of the mind and not its chastisement. They should remember their pleasures with gratitude, as they would the harvest of a summer.
We should wipe two words from our vocabulary: gratitude and charity. In real life, help is given out of friendship, or it is not valued; it is received from the hand of friendship, or it is resented.