「人老心不老」是young at heart，thinking and behaving as if you are younger than you really are，行為思想比實際年齡年輕，就是young at heart；例如︰My uncle is 90 but he’s still young at heart.
根據研究，原來young at heart真有延年益壽的功效。新聞報道的標題”People who feel younger at heart live longer”(〈心境青春活得長〉)，清晰直接點出心境和壽命的關係︰
Everyone dies, but a new study says feeling sprightly might suggest a person has more time left than people who feel their age or older. Older people in the UK who felt at least three years younger than their chronological age were less likely to die over the next eight years than those who felt equal to or older than their actual age, researchers found.
Sprightly解lively、full of energy，精神矍鑠的、輕快的。這個字多用來形容老人家，例如︰My aunt was quite sprightly for her age.
Chronological解按時間的、按年代序的。 Chronological age是實際的年齡。六千多個研究對象中，八年後，覺得自己比實際年齡年輕的、心態與實際年紀一樣，及自覺比實際年歲老的人，死亡率分別是14%、19%和25%。
性格決定命運
科學家推想這是因為︰”People who feel older are less likely to go out and about, are lonelier, are less mobile and are less physically active.”心境衰老的人把自己困在家中，較孤寂、不活躍。研究進一步證明，”perceptions(感覺、看法) of aging can have real consequences(後果) for the health of older individuals”。
有份參與研究的一位學者說：The findings show the need for society, which often influences these perceptions, to concentrate(專註) its efforts on enabling older individuals to view the process of growing old in a more positive(正面的) light.
另外，有研究亦發現︰”personality(性格) can so be tied to your destiny”，這就是性格決定命運。
New research into the link between personality and aging finds that there are two main traits that seem to help people live a longer life: conscientiousness(按良心辦事、認真，責任心) and optimism(樂觀).
智者有這樣的觀察：”People don’t grow old. When they stop growing, they become old.”(人不會老。只是有一天他們不再成長，那就真會變老。)Young at heart不只是關乎老年人，人長大後亦應努力保持心境青春。
常說歲月催人，但Deepak Chopra在Ageless Body, Timeless Mind: The Quantum Alternative to Growing Old就說這只是心態問題：
Age is reversible(可逆轉的). Biological age does not correspond to chronological age. You can be chronologically twenty years old, but if you’re emotionally and physically burnt out(精疲力盡), your biology will be that of an old person. Or you can be 70 years old and be physically, emotionally and spiritually fit and your biology reflects the stamina(耐力), the vitality(活力), the creativity, the alertness, and the dynamism(活力) of youth.
他在書中教了很多令青春常駐的心法：”Be natural; relinquish the need to hide constantly behind a social mask.”(活得真實；不再時刻以假面目示人。)”Be defenseless, relinquishing the need to defend your point of view.”(放下戒心，不再老說我對你錯。)
