Now that summer vacations are coming to an end, many of us are left with the burning question: Why do some people have great vacations while others come home feeling disappointed or blue? The answer may be that many of us do not think about vacations as carefully as we ought to.

"Often we are so busy focusing on family obligations and career goals that we don't give our leisure time the attention it deserves," says Stephen A. Shapiro, psychotherapist and coauthor with Alan J. Tuckman of Time Off: A Psychological Guide to Vacations (Anchor/Doubleday). "Choosing and planning a successful vacation is an art that often must be learned." There also are some common beliefs that must be unlearned.

Consider the following 10 statements. Decide whether each one is true or false. Then read on to see if you have answered correctly. Be prepared for some surprises.

1. You should take regular vacations -- even when you don't feel you really need them. TRUE FALSE

2. You can have a real vacation just lounging around the house. TRUE FALSE

3. A vacation should offer a complete change of pace from your normal life. TRUE FALSE

4. Vacation time is precious. Not a moment should be wasted. TRUE FALSE

5. Spur-of-the moment vacations often are disappointing. TRUE FALSE

6. The biggest vacation hurdle most couples face is agreeing on where to go. TRUE FALSE

7. Vacationing together is a good way to resolve marital problems. TRUE FALSE

8. People who go on vacation seeking relaxation or intellectual enrichment have more fun than people who are seeking escape or adventure. TRUE FALSE

9. When vacationing with the children, you should spend all your time with them. TRUE FALSE

10. Workaholics find it very difficult to relax while on vacation. TRUE FALSE ANSWERS:

1. TRUE. Most people think of vacations as a cure for exhaustion. But such respites from the daily grind can be postponed too long -- until you're an emotional basket case. Vacations should be thought of as preventive medicine to be taken before the mind turns to mush. Frayed nerves, a hair-trigger temper, insomnia, headaches, depression and feelings of being overwhelmed by life are all signs that you need a break.

2. FALSE. The key to a successful vacation is not just getting out of the office but also getting out of the house, where familiar surroundings and responsibilities usually defeat attempts to truly relax. If you think that the only alternative is a tiring, long-distance trip, you may be defining vacations too narrowly. "A vacation doesn't have to involve extensive travel," says Marilyn Machlowitz, a management consultant to major corporations. "Retreating to a weekend home or renting a country place is one alternative," she says, "or checking into a nearby hotel just to enjoy a refreshing change of scene and the luxury of room service."

3. FALSE. While change can contribute to the success of a vacation, too much change is ill-advised. Often, vacations are less than satisfying because people try to do so many new things at once and discover -- too late -- that they have bitten off more than they can chew. Take, for instance, comfort-loving couples who go backpacking, only to discover that the wonders of nature include unpredictable weather, predictable mosquitoes and hard, lumpy ground that makes them wish they had brought along a mattress instead of sleeping bags. Says Machlowitz: "A good vacation usually offers a balance between familiar things to do and new experiences. If you swim regularly, don't go someplace that doesn't have a pool. You'd be amazed how many people do just that." She also warns that if you're not already a camping buff, you might want to think twice before heading for the woods.

4. FALSE. People who keep up the same hectic pace on their vacation as they do in their everyday lives are called "spillover people" -- their run-run-run attitude spills over into their relaxation time. They may set a detailed agenda for each vacation day: breakfast at 9, tennis at 10, shopping at 11, lunch at noon, and so on from morning until night. Whew! Package tours that cram a maximum amount of sightseeing into a minimum amount of time are designed for this type of vacationer. But no one can keep such a hectic pace and continue to respond to each new experience with energy and enthusiasm. Sooner or later, the mind and the body shut down. Spillover people are often more exhausted when they come home from a vacation than they were when they left.

Even people who are returning from a relaxing vacation, however, should allow for some readjustment time before plunging back into normal life. People who return home at the last minute often suffer reentry shock that can cause them to feel depressed, anxious, irritable or exhausted -- all of which can negate the beneficial effects of even the best vacation. Plan on a transitional day or two to come down from your vacation high and readjust to the "real world."

5. TRUE. Spontaneity seldom makes for wonderful vacations. Keep a "wish list" of vacation ideas that appeal to you. Whenever you hear or read about an intriguing idea, add it to your list. (Otherwise, even the best idea might be forgotten.) Then, when the time comes to pick and plan, you'll have plenty of options to consider. Don't wait until a month before your vacation to start your list. Start early. Start now! Give yourself room to dream. Vacation dreams that withstand the test of time rarely, if ever, go awry.

6. FALSE. Many couples who think they have fully communicated their vacation needs to each other discover, too late, that they have not. Couples may agree on where to go, only to learn that their reasons for selecting the destination are not at all the same. One couple, for example, went to Hawaii to "relax in the sun." But as it turned out, relaxing in the sun meant something completely different to each of them. He wanted to tour the islands, scuba dive and fish; by dinnertime he was bushed and ready for bed, eager to get an early start the next day. She wanted to lie on a beach, cool drink in hand. By dinnertime, she was also ready for bed, but she was anything but tired.

You may also have a hidden agenda that you should share with your partner. The more the two of you share all your needs with each other, the more likely it is that your vacation will be all that you hope for.

What if, in discussing your vacation needs, you find that those needs are worlds apart? Many people fear that taking separate vacations will jeopardize their relationship. But if your relationship is sound, separate vacations will not threaten it. Far from creating problems, spending a week or two apart may actually help to strengthen your marriage. Take the kids or a friend along, or set out alone and do what you really want to do. You can have a terrific time and still miss each other. Briefly distancing yourself from a good relationship may well renew faded romance. Don't be surprised if you find candy or flowers awaiting you on your return.

7. FALSE. It may work on "The Love Boat," but it rarely works in real life. Going on vacation in the hope of resolving marital problems is more likely to result in a miserable vacation than in a better relationship.

8. TRUE. According to a 1980 survey conducted by Psychology Today, people who went on vacation to relax, to be with their family or improve their mind had a better time than did people who were seeking adventure or escape -- possibly because the latter were hoping to compensate for the bleak realities of their daily lives. The survey indicated that escapists were most likely to feel unfulfilled at work, bored at home and unhappy upon returning from vacation. Of course, this doesn't mean that anyone who seeks escape will be disappointed. But it does mean you should keep expectations realistic. Even the most exciting vacation cannot compensate for an unfulfilling life.

9. FALSE. Children need time away from their parents just as parents need time away from their children. Yet many well-intentioned parents suffocate their kids with attention while on vacation. Older children need a little freedom: an allowance to spend as they wish; a hotel room of their own that allows them some independence and offers you and your spouse a chance to be alone. Allowing older children to spend the evening watching TV in their room frees you and your spouse to enjoy an evening out without the distraction of squirming kids who would rather be somewhere else. And your children will probably have more fun spending an evening without parental scrutiny. Many resorts provide baby-sitting services and supervised activity programs for younger children. Ask about such services in advance.

10. TRUE. Most workaholics feel too driven, pressured or guilt-ridden to completely relax while on vacation. Does this sound like a description for your spouse or you? Then do something shocking: Bring work along! Knowing that you can work if the impulse strikes may enable you to relax and enjoy your vacation more than you would if your work were out of reach: As long as you have a marvelous time, any means justifies the end.