There is a photo in my collection that I pull out from time to time to remind myself of an old vacation. It’s a picture of me from the late 1970s on a bench in London’s Victoria Station, my head resting against a wall, eyes closed with tiredness, clothes messed up.

I used to love that shot. It was evidence of my leisure time, of travel, of interruption from the office: miles covered, sights seen, train stations raced through, goals achieved.

However, as I leave work to hit the vacation trail this summer, I take along something extra. This traveling companion has a habit of ruining trips with feelings of guilt—the guilt that comes from attempting to vacation while thinking of the job.

The conflict between the time we want off and the guilt we feel when we actually give in to leisure is a long-running battle that has gone too far, driven by an over-scheduling craze. It has made many feel as if their free moments are a form of truancy (玩忽职守).

It’s hard to take it easy when you’ve been programmed not to. We have been taught for generations that work is the only goal.

Time that is unfilled is evil, we are led to believe, and unplanned enjoyment should be avoided. This is reinforced today by a workplace culture that wants you to believe that advancement depends on your staying on the job.

Research now shows, however, that leisure time can do something job advancement and money can’t. Leisure activities increase your desire to work leadership skills, your sense of awareness and your ability to change. Free time also promotes a positive mood and sense of well-being, because it develops self-worth. Deep down, everyone knows we need time off to make our lives better.

On holiday, using your productive output as a measure of yourself doesn’t work. This is because a vacation isn’t about output; it’s about input — exploring, learning, reflecting. The magic of a holiday is in the experience itself. This is the same as life satisfaction; it can’t be measured, only felt.

The best part of a vacation isn’t going somewhere else; it’s being where you are, fully involved in the experience.

Conventional wisdom says that hardship can make us old before our time. In fact, a new study suggests that violence not only leaves long-term scars on children’s bodies, but also changes their DNA, causing changes that are equal to seven to ten years of premature aging.

Scientists measured this by studying the ends of children’s chromosomes (染色体）, called telomeres(端粒), says Idan Shalev, lead author of a study published in Molecular Psychiatry.

Telomeres are special DNA sequences (序列）which prevent the DNA in chromosomes from separating. They get shorter each time a cell divides, until a cell cannot divide any more and dies.

Several factors have been found to shorten telomeres, including smoking, radiation and psychological stresses such as being treated badly when young and taking care of a chronically ill person.

In this study, researchers examined whether exposure to violence could make children’s telomeres shorten faster than normal. They interviewed the mothers of 236 children 3t ages 5, 7 and 10, asking whether the youngsters had been exposed to domestic violence between the mother and her partner; physical maltreatment by an adult; or bullying. Researchers measured the children's telomeres —in cells obtained by wiping the insides of their cheeks一at ages 5 and 10.

Telomeres shortened faster in kids exposed to two or more types of violence, says Shalev. Unless that pattern changes, the study suggests, these kids could be expected to develop diseases of aging, such as heart attacks or memory loss, seven to 10 years earlier than their peers.

Shlev says there is hope for these kids. His study found that, in rare cases, telomeres Better nutrition, exercise and stress reduction are three things that may be able to lengthen telomeres, he says.

The study confirms a small but growing number of studies suggesting that early childhood adversity imprints itself in our chromosomes, says Charles Nelson, a professor of pediatrics and neuroscience at Harvard Medical School.

I heard many parents complaining that their teenage children are rebelling(叛逆)．I wish it were so．At your age you ought to be growing away from your parents．You should be learning to stand on your own two feet．But take a good look at the present rebellion．It seems that teenagers are taking the same way of showing that they disagree with their parents．Instead of striking out boldly on their own, most of them are clutching(紧握）at one another's hands for reassurance．

They claim they want to dress as they please．But they all wear the same clothes. Then set off in new directions in music．But somehow they all end up with listening to the same record together．Their reason for thinking or acting in thus-and-such a way is that many people are doing it．They have come out of their cocoon(茧)into a larger cocoon．

It has become harder and harder for a teenager to stand up against the popularity wave and go his or her own way．Industry has firmly carved out a teenage market．These days every teenager can learn from the advertisements what a teenager should have and be．

And many of today's parents have come to award high marks for the popularity of their children．All this adds to a great barrier(障碍） for the teenager who wants to find his or her own path．

But the barrier is worth climbing over．The path is worth following, You may want to listen to classical music instead of going to a party．You may want to collect rocks when everyone else is collecting records．You may have some thoughts 'that you don't care to share with your classmates at once, well, go to it．Find yourself．Popularity will come-with the people who respect you for who you are．That is the only kind of popularity that really counts．