Grown-ups are often surprised by how well they remember something they learned as children but have never practiced ever since. A man who has not had a chance to go swimming for years can still swim as well as ever when he gets back in the water. He can get on a bicycle after many years and still ride away. He can play catch and hit a ball as well as his son. A mother who has not thought about the words for years can teach her daughter the poem that begins “Twinkle, twinkle, little star” or remember the story of Cinderella or Goldilocks and the Three Bears.

    One explanation is the law of overlearning, which can be stated as follows: Once we have learned something, additional learning trials will help strengthen the related knowledge and skills.

    In childhood we usually continue to practice such skills as swimming, bicycle riding, and playing baseball long after we have learned them. We continue to listen to and remind ourselves of words such as “Twinkle, twinkle, little star” and childhood tales such as Cinderella and Goldilocks. We not only learn but overlearn.

    The multiplication tables (乘法口诀表) are also an exception to the general rule that we forget rather quickly the things that we learn in school, because they are another of the things we overlearn in childhood.

    The law of overlearning explains why cramming for an examination, though it may result in a passing grade, is not a satisfactory way to learn a college course. By cramming, a student may learn the subject well enough to get by on the examination, but he is likely soon to forget almost everything he learned. A little overlearning, on the other hand, is really necessary for one's future development.

    Two of the saddest words in the English language are "if only". I live my life with the goal of never having to say those words, because they convey regret, lost opportunities, mistakes, and disappointment.

    My father is famous in our family for saying "Take the extra minute to do it right." I always try to live by the "extra minute" rule. When my children were young and likely to cause accidents, I always thought about what I could do to avoid an "if only" moment, whether it was something minor like moving a cup full of hot coffee away from the edge of a counter, or something that required a little more work such as taping padding (衬垫) onto the sharp corners of a glass coffee table.

    I don't only avoid those "if only" moments when it comes to safety. It's equally important to avoid "if only" in our personal relationships. We all know people who lost a loved one and regretted that they had foregone an opportunity to say "I love you" or "I forgive you." When my father announced he was going to the eye doctor across from my office on Good Friday, I told him that it was a holiday for my company and I wouldn't be here. But then I thought about the fact that he was 84 years old and I realized that I shouldn't give up an opportunity to see him. I called him and told him I had decided to go to work on my day off after all.

    I know there will still be occasions when I have to say "if only" about something, but my life is definitely better because of my policy of doing everything possible to avoid that eventuality. And even though it takes an extra minute to do something right, or it occasionally takes an hour or two in my busy schedule to make a personal connection, I know that I'm doing the right thing. I'm buying myself peace of mind and that's the best kind of insurance for my emotional well-being.

    If you're new to San Francisco, paying the city a visit, or simply looking for a new playground for you and your dog, here are four of the finest dog parks in San Francisco.

    Corona Heights Dog Park

    Often visited by residents from all over the city because of its nearness to the Randall Museum, Corona Heights Dog Park offers pets and owners breathtaking views, after a steep hillside climb, and a fenced dog area that allows dogs to let loose without a leash （狗链）. Owners will also enjoy the playground, tennis courts and basketball courts.

    Dolores Dog Park

    The grounds of Dolores Park once served as camps for those who were left homeless by the 1906 earthquake, but now often visited by crowds of Mission District people. Four-legged friends can also wander about carefree off-leash while making friends with other members of the doggie community.

    Pine Lake Dog Park

    Noteworthy for its place as a rest stop for hundreds of species of birds to fly to and from warmer climates, Pine Lake Park is also prized by city dogs and their owners for their nice hiking paths, picturesque lake suited for swimming, and an off-leash area on the park's west end that lets dogs run free.

    Buena Vista Dog Park

    At 146 years young, Buena Vista Park is San Francisco's oldest park. Dogs and owners with plus energy will love burning it on this park's steep paths and winding staircases. Dog owners should have good control over their dogs, as it's quite easy for dogs to get separated when going through Buena Vista's many twists and turns.

    The idea of progress started to flower in the 17th century. At that time, many wise thinkers believed that man liberated（解放） by reason would rise to greater heights of achievement. The many expressions of human nature would be the engines of progress: language, business, science, and moral sensibility （道德感）. Unfortunately, most of those engines have failed to bring the desired human progress.

    The modern age has belonged to material progress and its main source has been science. Science gives people huge power to change the world. But can people be trusted to use it always for good? Think of biotechnology and information technology. And it is not just that scientific progress does not deliver the emotional good. People also fear that mankind is failing to manage science properly. The forests are disappearing; the ice is melting; privacy is leaking; life is becoming a depressing march in an ugly world.

    The point is not that science is harmful, but that scientific progress needs to be mapped tidily onto human progress. That relies on moral sensibility in its widest sense. This liberal force offers hope for a better future. The very idea of moral sensibility probably sounds out-of-date. Bur researchers find that people desire a sense of moral purpose which would give life dignity （尊严）. People want to determine how the world works, not always to be determined by it. Moral sensibility is why people will suffer from their beliefs, and why acts of noble self﹣sacrifice are so powerful.

    It is admitted that our moral ideals will never be realized completely. But sometimes, however imperfectly, we can make progress. Human dignity requires the love of ideals for their own sake, but nothing requires that the love be returned.

Human progress is neither guaranteed nor hopeless. Instead, it is up to us.

    Psychology has a new application in the field of medicine. Many doctors, together with their patients, are looking for alternative methods of treatment of physical problems. In large hospitals, modern therapy(疗法)seems to focus on the physical disease. Patients may feel they are treated like broken machines. Some doctors have recognized this as a problem. They are now using psychological therapy, in which the patient is working with the doctors against the disease with the help of medicine. The patient does not wait for the medicine and treatment to cure him or her, but instead the patient joins in the fight.

    The doctor knows that a disease affects a patient's body physically. The body of the patient changes because of the disease. He is not only physically affected, but also has an emotional response to the disease. Because his mind is affected, and his attitude and behavior change. The medical treatment might cure the patient's physical problems, but the patient's mind must fight the emotional ones. For example, the studies of one doctor, Carl Simonton, M.D., have shown that a typical cancer patient has predictable attitudes. She typically feels depressed, upset, and angry. Her constant depression makes her acts unfriendly toward her family, friends, doctors, and nurses. Such attitudes and behaviors prevent recovery. Therefore, a doctor's treatment must help the patient change that. Simonton's method emphasizes treatment of the "whole" patient.

    The attitude of a cancer patient receiving radiation therapy, an X-ray treatment, can become more positive. The physician who is following Simonton's psychological treatment plan suggests that the patient imagine that he or she can see the tumor(肿瘤)in the body. In the mental picture, the patient "sees" a powerful beam of radiation like a million bullets of energy. The patient imagines the beam hitting the tumor cells and causing them to shrink. For another cancer patient, Dr. Simonton asks him to imagine the medicine going from the stomach into the bloodstream and to the cancer cells. The patient imagines that the medicine is like an army fighting the diseased cells and sees the cancer cells gradually dying and his blood carrying away the dead cells. Both the medical therapy and the patient's positive attitude fight the disease.

    Doctors are not certain why this mental therapy works. However, this use of psychology does help some patients because their attitudes about themselves change. They become more confident because they use the power within their own minds to help stop the disease.

    Another application of using the mind to help cure disease is the use of suggestion therapy. At first, the doctor helps the patient to concentrate deeply. The patient thinks only about one thing. He becomes so unaware of other things around him that he is asleep, or rather in a trance(催眠状态). Then the physician makes "a suggestion" to the patient about the medical problem. The patient's mind responds to the suggestion even after the patient is no longer in the trance. In this way, the patient uses his mind to help his body respond to treatment.

    Doctors have learned that this use of psychology is helpful for both adults and children. For example, physicians have used suggestion to help adults deal with the strong pain of some disease. Furthermore, such treatment may help the patient with a chronic diseases. Suggestion has been used to change children's habits like nail­biting, thumb­sucking, and sleep­related problems.

    Many professional medical groups have accepted the medical use of psychology and that psychology has important applications in medicine.