Ecclesiastes 5:19-20 (NLT)
19 And it is a good thing to receive wealth from God and the good health to enjoy it. To enjoy your work and accept your lot in life—this is indeed a gift from God. 20 God keeps such people so busy enjoying life that they take no time to brood over the past.

In these verses Solomon says one should reflect on the good parts of present life and forget about the misfortunes of the past. He says God will keep these people busy, doing well and enjoying life so their time is lessened to think of the past.

There have been people who have said something to the effect of, “If I could just have that I would be happy.” They finally obtain what they desire and again they find themselves unhappy longing for something new. Others look for the happiness in their circumstances. When things are going great; the world is a happy place. But when things go bad; the world is sad and exhausting. Some look for their happiness in others. As long as someone around them is happy they too are happy. But when anger or sadness arises in the other person; it turns into their own displeasure with life. Sometimes people escape to be happy. They turn to alcohol, drugs or other sinful pleasures just for a moment of happiness that soon fades away. These are all moments of false happiness. True happiness can only come from the inside when a person accepts their life for what it is. They allow God to show them their purpose and they learn to accept what is good around them. They find contentment and joy that fills their heart. They are satisfied with the love of God and what He offers in life. So take time each day and look at the good things God has given you and you will soon find the happiness God meant for you to have.