Don't Worry, Be Happy
The more you worry, the more you dig yourself an early grave. Worrying is spending your precious moments of the present on some potential future which has not and may not even happen. You burn energy on a work of fiction, and you can literally make yourself ill with such activity. This life only happens once, and if you waste it on such pursuits, you get no second chance.
The effects do not stop there. What you do affects the world around you. Your family and friends are affected by your moods. Imagine you throw a stone into a pond, and you see the ripples reaching outward from the centre. You are the centre and your family and friends are around you, reaching outwards. Those closest to you are the most affected by your moods. They in turn form the centres of their own circles, and so the reach of the influence is unknown, and usually more than you can imagine. In many cases the effects can be magnified.
If you concentrate on being happy, you see how much you have to be grateful for. Such an attitude of gratitude focuses you on the positive.
Some people might argue that there are things we should worry about. For such things I would use the word "concern" for. To be worried implies you are distressed, where as being concerned is more that you are aware of some issue and are being careful. You can be concerned and still happy with your lot in life.
By being happy you cheer others around you, and brighten their lives. They in turn reflect back their own happiness, and further enhance your life. It is a virtuous cycle, a positive feedback loop that drives all involved to new hights.
P.S. I added a new article on worrying.