When she looked ahead，Florence Chadwick saw nothing but a solid wall of fog.Her body was numb (麻木的)．She had been swimming for nearly sixteen hours.

    Already she was the first woman to swim the English Channel in both directions.Now，at age 34，her goal was to become the first woman to swim from Catalina Island to the California coast.

    On the morning of July 4th，1952，the sea was like an ice bath and the fog was so thick that she could hardly see her support boats.The wind was strong and it was raining heavily.Against the cold water of the sea，she struggled on—hour after hour.Millions of people at home were watching her in front of the television.

    In one of the boats，her mother and her trainer tried their best to encourage her.They told her it wasn't much farther.But all she could see was fog.They urged her not to give up.She never had...until then.With only a half mile to go，she asked to be pulled out.

    After thawing her cold body several hours later，she told a reporter，“Look，I'm not excusing myself，but if I could have seen land I might have made it.” It was not tiredness or even the cold water that defeated her.It was the fog.She was unable to see her goal.

    Two months later，she tried again.This time，despite the same thick fog，she swam with all her strength and her goal clearly pictured in her mind.She knew that somewhere behind that fog was land and this time she made it! Florence Chadwick became the first woman to swim the Catalina Channel!  

    Grown­ups 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(尝试)increase the length of time we will remember it.

    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 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(突击学习)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.

    For students at The Farm School in Hamilton, Virginia, the classroom is outside-every day.

Jaclyn Jenkins is a founder of the school. "The number one question immediately we get from parents is 'what happens if it rains?' And we say, 'Bring an extra pair of clothes!'" Jenkins adds, "We still educate them. They also get energy. Their brains are working when they're moving. So, our goal is to always be outside."

    The Farm School is a preschool-a place for three-and four-year-olds to learn and play. Teacher Alison Huff has taught at other schools. She says The Farm School gives its students more of a hands-on learning experience. For example, children use pumpkins to learn about colors and counting. They learn about measurements by planting seeds 30 centimeters apart. Huff says "We can use everything a regular preschool uses, but out in the garden."

Apart from planting vegetables and fruits, students help prepare food and clean up afterward. The school teaches the children to cook using the food they have grown. "They can see the advantages of what they have in the garden and taste it then instead of going to the grocery store and buying it," Huff says.

    The preschoolers also lean words in languages other than English. Huff speaks in both English and Spanish. Her assistant speaks French and Arabic. She adds that a 3-year-old in her class speaks four different languages.

    Farm animals are also an important part of the education program. Jaclyn Jenkins says the children learn about a different animal every month. Two months ago, she says, that animal was a cow. The children spent another month with a large bird-a turkey.

    The children come home with new experiences, new knowledge and sometimes a few vegetables.

The thing that sets children apart from adults is not their ignorance, nor their lack of skills. Rather, it's their enormous capability for joy. A friend told me a story. One day, when she went to get his 6-year-old son from soccer practice, her kid greeted her with a sad face. The teacher had criticized him for not focusing on his soccer drills. The little boy walked out of the school with his head and shoulders hanging down. He seemed wrapped in sadness. But before reaching the car door, he suddenly stopped, crouching(蹲伏) down to look at something on the sidewalk. “Mom, come here! This is the strangest bug I've ever seen. It has, like, a million legs. It's amazing!” The little face was overflowing with indescribable excitement.

Nowadays, however, when we walk into a classroom, especially in a high school, we'll be choked by towering books and papers, and hiding behind them are a group of motionless creatures, pens in hand, minds dry, just as the hollow men portrayed by T. S. Eliot. Their pursuit of joy has given way to their hunger for grades. Laughter and happiness are a distant memory for them.

    Although joy is an unaffordable luxury in today's increasingly fierce competition, administrators and teachers need a mindset shift from crushing students with assignments to getting them to take pleasure in productive activities which develop their important qualities, like perseverance and obligation. The assumption that pleasure is the enemy of competence and responsibility makes no sense educationally.

Adults tend to talk about learning as if it were medicine: unpleasant, but necessary and good for you. Why not think of learning as if it were food—something so valuable to humans that they want to experience it as a pleasure?

    In 2015, a man named Nigel Richards memorized 386, 000 words in the entire French Scrabble Dictionary in just nine weeks. However, he does not speak French. Richards' impressive feat is a useful example to show how artificial intelligence works—real AI. Both of Richard and AI take in massive amounts of data to achieve goals with unlimited memory and superman accuracy in a certain field.

    The potential applications for AI are extremely exciting. Because AI can outperform humans at routine tasks—provided the task is in one field with a lot of data—it is technically capable of replacing hundreds of millions of white and blue collar jobs in the next 15 years or so.

    But not every job will be replaced by AI. In fact  four types of jobs are not at risk at all. First, there are creative jobs. AI needs to be given a goal to optimize. It cannot invent, like scientists, novelists and artists can. Second, the complex, strategic jobs—executives, diplomats, economists — go well beyond the AI limitation of single-field and Big Data. Then there are the as-yet-unknown jobs that will be created by AI.

    Are you worried that these three types of jobs won't employ as many people as AI will replace? Not to worry, as the fourth type is much larger: jobs where emotions are needed, such as teachers, nannies and doctors. These jobs require compassion, trust and sympathy—which AI does not have. And even if AI tried to fake it, nobody would want a robot telling them they have cancer, or a robot to babysit their children.

    So there will still be jobs in the age of AI. The key then must be retraining the workforce so people can do them. This must be the responsibility not just of the government, which can provide funds, but also of corporations and those who benefit most.

    Parents do not owe (欠) their children a college education. If they can afford it, they can certainly send them to a good university. But they needn't feel guilty if they can't. When children grow up and want to get married, their parents do not owe them an apartment. They do not have the duty to look after their grandchildren, either. If they want to do it, it must be considered a favor, not an obligation.

    Do parents owe their children anything? Yes, they owe them a great deal.

One of their obligations is to give their children a personal worth. Children who are always made to feel stupid and unworthy, constantly compared with brighter brothers, sisters, or cousins will become so unsure, so afraid of failing that they won't try at all. Of course they should be properly corrected when they do wrong, but it's often better to let children learn their mistakes by themselves in time. All their parents should do is to trust them, respect them, understand them and give them chances to try and fail. They must learn to stand failure. When criticisms (批评) are really needed, they should be balanced with a smile and a kiss. That is the way children learn.

    Parents owe their children a set of solid values around which to build their lives. This means teaching them to respect the rights and opinions of others; it means being respectful to elders, to teachers, and to the law. The best way to teach such values is by deed. A child who is lied to will lie. A child who sees no laughter and no love in the home will have difficulty laughing and loving.

No child asks to be born. If you bring a life into the world, you owe the child something.