WHEN A WAITER at a restaurant has one table, he usually isn't stressed at all. He can concentrate and do a good job, and it is no problem. Two tables, okay. Still no problem. Three tables, and he has to start paying attention, because it's like juggling — the more balls you have in the air, the easier it is to drop one. When he gets up to seven or eight tables, it can become very stressful. The juggling of tasks becomes too complex to handle well.
In the same way, the number of purposes you have is directly related to your stress hormone level. Depending on how you handle your goals, a strong sense of purpose can help you manage stress well, or it can make your general stress level much worse.
The problem is that the natural drift for people is toward complication. In other words, if you don't try to do anything about it, your life will get more and more complicated; you will collect more and more purposes. So you have to make a continuous effort to simplify your purposes. Your life will naturally and constantly drift toward complication, just as a rose bush will constantly try to sprawl. You must continually prune. You can't prune once and for all. You have to keep pruning.
For example, the waiter had several goals. He wanted his guests to be happy. He also wanted to get along well with his fellow waiters. And he wanted to please the cooks so interactions with them were pleasant. And, of course, he wanted the managers to be happy with him. And so on. Too many purposes. His attention is scattered in too many directions. If he knew about simplifying purposes, he would have trimmed his purposes down to something manageable: To make the guests pleased with his service. That's enough to concentrate on, and that would keep his tension level lower, because it is manageable.
Manage your purposes. Make a list: What are your most important purposes? Trim the list down to something manageable; something simple enough that you can manage it without stress. Get few enough purposes that it feels good.
Having strong purposes can improve your mood tremendously, but only if you keep your purposes trimmed down enough to feel good.
Be aware that after you trim your purposes, complexity will gradually creep back in. Simplifying your purposes is something you'll need to do once in awhile for the rest of your life.
Keep your purposes strong and clear, simple and heartfelt, and you will find the most powerful source of self-generated happiness that exists in this world. As George Bernard Shaw said, "the true joy in life is being used by a purpose recognized by yourself to be a mighty one." Experience the true joy in life. Be used by a mighty purpose. Find yourself a concrete assignment that demands fulfillment and get to work.